VMS Sentinel Red Head

[Chris Ringrose]

Had a go on a shiny new VMS Sentinel Red Head today. New units now being manufactured. The Sentinel lives again!

https://youtu.be/RMPFNneQ858

Very nice work of breathing. OLED displays, CO2 sensor and full tri-mix capability as standard. Completely redesigned head includes new O2 sensor module and PPO2 tracking algorithm.

Enjoy!

Chris

[JPTaylor]

deleted

[flyingfisheye]

Why would you have to be retrained, John?

[Jackdiver]

I have a Red Head.
There is no crossover training required.

[Doomanic]

How much is a complete Redhead? I can't see a price on the website.

[Jackdiver]

How much is a complete Redhead? I can't see a price on the website.

Mine's an upgrade, but I think Martin posted on Facebook a price of £7950 inc VAT.

[nickb]

Mine's an upgrade, but I think Martin posted on Facebook a price of £7950 inc VAT.So, a lot more than a Vision or a JJ (and probably a rEvo too) then?

The phrase 'You can't polish a turd' seems apt here.

[Rob Dobson]

Is it still the size of a fridge, still have that awful UI and does it still give you every reason it can think of why you can't do the dive?

[gobfish1]

Did they name it after that other Infamous red head ,


Snake oil would be a better name ,

[jamesp]

So, a lot more than a Vision or a JJ (and probably a rEvo too) then?

The phrase 'You can't polish a turd' seems apt here.

But a JJ resembles triggers broom after 250 hours due to all the bits that get replaced, how much did that add to the cost?

[flyingfisheye]

I was wondering what the big down is on the Sentinel? people who have one I guess like them and VMS must do to have the faith to invest their time and money in to it's future. I wonder how many of the people slating them actually have dived one, for more than a try a dive? When you look at the figures for the Scrubber and the set point etc seams a good unit. Was it not designed to engineer out some of the early user induced fatalities?

[nickb]

But a JJ resembles triggers broom after 250 hours due to all the bits that get replaced, how much did that add to the cost?A lot less that you'd like to imagine, thanks to the very generous support offered by the company.
JJ-CCR aren't in the business of vertical marketing or roping people into a shit product that needs money pumped in to keep it working. Virtually everything I've ever needed has been sent-out for free or at cost.

[nickb]

I was wondering what the big down is on the Sentinel? people who have one I guess like them and VMS must do to have the faith to invest their time and money in to it's future. I wonder how many of the people slating them actually have dived one, for more than a try a dive? When you look at the figures for the Scrubber and the set point etc seams a good unit. Was it not designed to engineer out some of the early user induced fatalities?The 'down' is the over-engineering that renders the thing virtually undivable for most users.

I know a few Sentinel divers that never seem to have problems with their rebreathers but these are guys who really have their shit sorted. The sort of chumps that rock-up on UK dive boats lugging these huge piles of shit mostly spend their time reading the handsets and watching other people, usually on Inspos or JJs, having fun diving.

I don't need to own or dive one to realise that they are crap.

I don't need to dive sidemount to understand that it's just another thing for mostly shit divers to try in order to waste money. Likewise, I don't need to have Ebola to realise that it would put a big crimp in my day.

[MikeF]

Disclaimer - i have never dived one and this is my personal observations from spending a few weeks diving with 2-3 people using them (5 in total 2 on one trip and three on another) where every unit has developed a fault after a couple of days use (that's not to say other rebreathers don't develop issues and I've seen plenty of broken inspos and the odd JJ but not every unit) and on balance I'd say the issues with the sentinels have been more terminal and couldn't be worked around short of a complete head change to continue diving.

having a geeky streak and being an engineer it struck me as an 'overengineered' product and the phrase 'an engineer is a man who can do for five shillings what any fool can do for a pound' and the question 'just because you can do something did you pause to think whether you should?' immediately sprang to mind.

It appeared that in the quest to produce a premium product that ticked every box imaginable the usual principles of minimalist 'fit for purpose' design, material selection, design for manufacture and maintenance, ease of operation and ergonomics appear to have been sacrificed to the alter of 'throw money at it to make it look like a premium product'.

In a nutshell it stuck me as overly complicated and unreliable. It utilises expensive materials and manufacturing processes, it's not fantastically designed when it came down to detail and the build quality is a bit iffy and it's bloody massive and heavy. However I believe the WOB is very good, scrubber usage is very efficient and it's got some flashy lights that occasionally work.

most people I've talked to who use them appear to be trapped with a CCR that they spent an awful lot of money on and is now pretty worthless on the second hand market. If the red head adresses the reliability issue of the electronics it may have some future but the existing owners are still screwed unless they fork out the price of a a reasonable s/h vision or JJ to junk the existing head and replace it.

I'd do the latter if I had one as both the vision and JJ will take any sane person further than they'd want to go, again just my opinion made on observations of each unit being used in real life.

[Rob Dobson]

.....I wonder how many of the people slating them actually have dived one, for more than a try a dive?

I wonder how many people who own them have actually done more than a try dive with it. My experiences of being on dive boats with Sentinels are that they either don't jump in due to some error message, call it at the top of the shot due to some error message or those that have made it down the shot seem to turn around and head straight back to the boat where they spend the next few hours staring at the handsets and muttering to themselves.

I never saw anything like the number of dives canned on Inspo's, Revo's, JJ's, Megs - even home builds *combined*. Sentinels were the units I saw the least and can hardly remember ever seeing one complete a dive.

[Jackdiver]

I've had mine since the beginning of 2009 and have done hundreds of hours on it, I've never missed a dive or had a major fault.
I've just come back from another Redsea trip with the Red Head. Again faultless.

[nickb]

I've had mine since the beginning of 2009 and have done hundreds of hours on it, I've never missed a dive or had a major fault.
I've just come back from another Redsea trip with the Red Head. Again faultless.You clearly have one of the few good ones. It's inevitable that some would sneak by whatever passed for quality control at VR.

Happy owners are few and far between and the dissatisfied ones are hardly likely to 'fess-up to how they pissed away more than £8k on a fucking doorstop.

[Rob Dobson]

I've had mine since the beginning of 2009 and have done hundreds of hours on it, I've never missed a dive or had a major fault.
I've just come back from another Redsea trip with the Red Head. Again faultless.

Good for you. If I had spent time with happy Sentinel owners it would have shaped my views on the units in a positive way. As it is I don't remember ever seeing happy Sentinel divers doing dives.

I know of three allied airmen who bailed out of aircraft during world war 2 at cruising altitude without parachutes who survived. It's possible but their experiences were not the norm.

[flyingfisheye]

Happy owners are few and far between and the dissatisfied ones are hardly likely to 'fess-up to how they pissed away more than £8k on a fucking doorstop.

I take it you are not the biggest fan then, Nick? I wonder how many dives missed was due to the owners not understanding their units? or the error messages? etc. Jack diver seams to like his. or may be it's a Swansea v Cardiff thing developing. ;-)

Shame some of the people who have one, don't say whats good about them, apart from using as an anchor or door stop.

what has the red head done that the old black head did not do?

Be nice to have a balanced view of the pros and cons.

[nickb]

I take it you are not the biggest fan then, Nick? I wonder how many dives missed was due to the owners not understanding their units? or the error messages? etc. Jack diver seams to like his. or may be it's a Swansea v Cardiff thing developing. ;-)Ah, a man who knows that Wales isn't one big homogenous lump of Taffs. We fucking hates those Jack bastards we does ;)


what has the red head done that the old black head did not do? That I do not know. I'm sure that Martin and his crew are endeavouring to produce a decent unit and I genuinely wish them well. However, the product is seriously tainted, just like the APOC, and things have moved-on. I can't think of a single reason why anyone looking to buy a CCR would even contemplate investing in a Sentinel.

[Tim Clements]

Dear all, particularly all you sentinel 'downers' out there.

OK, there are some serious information deficiencies here that need fixing.

1) No one is debating the past - the VR Sentinel did not do what it ssaid on the box. It was a rebreather with great performance, but the addition of unreliable sensors to the system to create an LSS was unsuccessful and did not result in an 'easier to dive' system. Lot's of failures, lots' of unhappy divers. I'm not arguing that, I was one of them

2) That's where we started at VMS - we like the idea of something that takes the legwork out of resource monitoring and so do many divers we have spoken to. So the concept of using a system to monitor these resources is OK and if that's what you like is a very good reason to buy a Sentinel. No one is being forced to like this, I completely recognise many divers do not want either additional complication, or information on their scrubber status, or early warning of CO2. How good is the human body at detecting CO2? Let's leave that to Simon Mitchell, but if you do want a sensor, again, buy a Sentinel, if you don't, fine, but please at least recognise that some people do.

3) How to make it work? OK we have spent 18 months and an extreme shitload of cash on this and we have a result. It is called the RedHead. We looked into how processes and sensors worked in the Sentinel and fixed it. We got rid of what had problems and made what worked more robust. The result is more flood resistance, better PO2 tracking, better work of breathing (both of which were never in doubt anyway) and most importantly a set of sensors that actually work. They respond to changes in resource level and reduce the effort required to monitor PO2, CO2, battery, scrubber time remaining (dynamically, thus warning of floods, poor material etc), HP O2 and HP Dil. You still need to know what you are doing, but the system now works. Do what you want with the extra time!

4) Additional benefits of the RedHead - it's approx 4kg lighter, modular so components can be swapped easily in the field, harder to flood and you can remove the electronics pod for travel. Standard unit, in a 5kg grey crate weighs 27kg all in, inc crate. Ready to dive around 34kG plus whatever weight you need personally. So the Sentinel is no longer so good as a paperweight or doorstop. It's lighter than a JJ. Sorry. It's rechargeable, brand new rechargeable PO2 module accessible from above - I could go on. Size - OK still the same, but lighter and guess what - small women can carry it up ladders after diving. The extra size assists with keeping the scrubber warm and contributes towards increased performance.

5) Benefits to existing Sentinel owners. Firstly, you can buy the RedHead as a simple swap, takes under an hour to change, no additional training required. Secondly, thanks to our efforts existing Sentinels are now worth more than zero, so we have prevented a total loss for many Sentinel owners out there. IF you choose, you could buy a second hand unit and put a RedHead upgrade on, replacing in one swoop ALL electronics and gaining any upgrades over previous functionality. Less paperweights / doorstops, more diving.

6) Unit price. £7950 comes out of the box ready to dive with a BOV, wing, cylinders, trimix enabled, fully independent backup computer with live deco, everything and it's assembled! Just price your way through an inspo, JJ or Revo and they are all in the same ballpark.

There are undoubtedly some people out there who will not suit a Sentinel. There will also undoubtedly be the odd dive missed for false positives, but these are now very much the exception and NO ccr is immune from failure.

In summary, there are now MANY reasons to buy a Sentinel redhead. If you genuinely respect the effort we have put in to support existing abandoned divers, fix and restore a CCR many people fell worthwhile, then please point divers at this summary. We stand by it and offer excellent backup and customer service in the UK. We promise we won't make any profit for ages - that's our problem, but we are sincere and deserve a chance that isn't simply shot down by the previous reputation.

Thanks for reading - if you would like any further info, just email info@vmsrebreathers.com or even, maybe book a trydive - the proof of the pudding is in the eating and we are confident that even if the concept if not for you personally, you'll agree that it works well and will suit many other divers.

Cheers, Tim

[nickb]

6) Unit price. £7950 comes out of the box ready to dive with a BOV, wing, cylinders, trimix enabled, fully independent backup computer with live deco, everything and it's assembled! Just price your way through an inspo, JJ or Revo and they are all in the same ballpark. I can't be arsed to look at the current price of Inspos or rEvos but a CE DiveCAN JJ is currently €7190 plus VAT*. I make that less than £6200 using an exchange rate of €1.40/£1 (it's currently better than that).

If you think that £1000 price difference is 'ballpark' I would question your judgement on the other stuff you've written.

* http://jj-ccr.com/media/29696/jj-ccr_pricelist_q3_2014.pdf

[Tim Clements]

Nick, at least add an independent computer and allow for a BOV, It's ballpark now. The Revo was quoted at more at TekDive 2015 last weekend and a chap who enquired on Sunday about a redhead had reached an estimate for equivalent Inspo of £9000, Now that seems high, so I'll go with 'ballpark'.

Then read the rest and admit we're trying to do something worthwhile.

I'm not offering a judgement, I'm telling you what we are trying to do - you don't have to like it, seems like you are determined not to, others will feel differently.

Since you can't be arsed to find out facts, I'ld question everything else you have written.

[nickb]

Nick, at least add an independent computer and allow for a BOV, It's ballpark now. The Revo was quoted at more at TekDive 2015 last weekend and a chap who enquired on Sunday about a redhead had reached an estimate for equivalent Inspo of £9000, Now that seems high, so I'll go with 'ballpark'.The price difference is £1750, I missed-out the word 'over'. As I understand it, a Shrimp can be had for £400-odd and If I didn't already have a backup computer, I could pick-up a 2nd-hand Petrel for around the same. You're still out by almost a grand.

I could add a NERD to a JJ for less than the difference in price. But that wouldn't be comparing like for like, even you are not going to try and pretend that the computers attached to the Sentinel come anywhere close to the products that Shearwater produce.


Then read the rest and admit we're trying to do something worthwhile.If you've read what I wrote yesterday, you'll have seen that I said something along those lines. I do, however, think you're dealing with something that has such a bad reputation, it would be better to start from scratch. At least do what other companies do with toxic brands and change the name.


Since you can't be arsed to find out facts, I'ld question everything else you have written.I found-out the fact I needed and posted a link. I couldn't care less what Visions or rEvos cost as I'm not ever likely to need to know.

[notdeadyet]

That's the big thing, Nick. The brand. 8 grand for a "maybe" unit. It's only a matter of time before soneone says "early adopter".

It's a couple of grand away from a 15.5, and a couple of grand more than proven units.

It all sounds like paying for VR's past mistakes. You're asking punters to pay for a shit design to be put right.

It's all academic to me, I'm not looking for a new unit. There will always be someone who is but past performance and sheer size would rule it out for me alone.

Sent from my GT-I9300 using Tapatalk

[Baron015]

As I understand it, a Shrimp can be had for £400-odd

My shrimp bought direct from Golem Gear in Dec 2013 cost $880, plus $89 for Rev D HUD holder, plus shipping, for total of $1,025.85. That is about £680 at todays exchange rates.

I've had a Sentinel. The pain points were in order 1. the HP sensors, TPM, electronics package, 2. the weight for transport etc, 3. ungainly size/shape/no stand.

The RedHead seems to have addressed point 1 and 2 completely, and slightly improves on 3 (weight) but still no stand or change in overall size/shape or a proper "travel frame". (Bring on G-Box for Sentinel, maybe if Graham BB gets really hard up he will apply himself to this problem)

So c.f. the JJ sure you lose out on the slimline can design and the nice Shearwater handset. But you gain CO2 monitor, TPM, O2/Dil rate monitoring, dual primary/slave handsets, deco on HUD, etc... For some people this will be reasonable trade one way or another. Worth looking at.

A working Sentinel has always been a delight to dive with once you are actually in the water.

[nickb]

My shrimp bought direct from Golem Gear in Dec 2013 cost $880, plus $89 for Rev D HUD holder, plus shipping, for total of $1,025.85. That is about £680 at todays exchange rates.Fair enough. I was going by this thread (http://www.thediveforum.com/showthread.php?18085-Golem-Gear-Shrimp) but, as I have no intention of buying one, I've never made enquiries.

CO2 monitors are of no interest to me at the current level of the technology.
Dil/O2 rate monitoring? WTF value does that have? I could do those calcs in my head.
Deco on HUD? Plug in a NERD (still cheaper than the Sentinel - see above)
TPM? I don't even know what that is.

[nickb]

A working Sentinel has always been a delight to dive with once you are actually in the water.That wasn't enough for you to stick with it though, was it mate?

Are you considering reverting back?

[Ron MacRae]

If I was to go for a rebreather I'd want one that did everything for me that it could. In the scheme of things £1000 is sod all if it delivers what you want. I would not like to have to keep monitoring lots of different stuff, I want to concentrate on the dive, not the kit.

I did a try dive, with Tim, a few years ago.
I liked the Sentinal green/red light and vibrating mouthpiece. Just swim about until the lights change no need to monitor extra stuff. Result.
What put me off was
1) The reliability reputation.
2) The fact that breathing fairly normally I could empty the counterlung, causing air injection, and then over inflate, causing bubbles, on every breath.

If they've fixed both of these then I might consider it again if I was doing enough diving to make it worthwhile.
At the moment I'm not. :(

I can see the reason for not changing the name if they're trying to get old sentinal users to upgrade.

[flyingfisheye]

I've had a Sentinel. The pain points were in order 1. the HP sensors, TPM, electronics package, 2. the weight for transport etc, 3. ungainly size/shape/no stand.

The RedHead seems to have addressed point 1 and 2 completely, and slightly improves on 3 (weight) but still no stand or change in overall size/shape or a proper "travel frame". (Bring on G-Box for Sentinel, maybe if Graham BB gets really hard up he will apply himself to this problem)

So c.f. the JJ sure you lose out on the slimline can design and the nice Shearwater handset. But you gain CO2 monitor, TPM, O2/Dil rate monitoring, dual primary/slave handsets, deco on HUD, etc... For some people this will be reasonable trade one way or another. Worth looking at.

A working Sentinel has always been a delight to dive with once you are actually in the water.

I was away on a trip recently (I was OC did 38 dives). there were 9 CCR divers, 1 rEVO, go wet for 10 minutes and failed day one owner went OC for the rest of the trip. 1 JJ worked for 2 weeks with out issue, apart from one LED in the HUD failed. 1 Meg worked fine for near 2 weeks until problem with solenoid ran manually for the remaining dives. 2 Ap EVO worked with out fault all 2 weeks, 3 AP Visions work without fault for 2 weeks. 1 Persidon 7 had initial operator issues on first day but then when a bit of training was given worked with out fault for the rest of the 2 weeks. All the guys on CCR dived with out balling out etc and all had a great time. I kind of wish I had taken mine too.

[Tim Clements]

https://www.facebook.com/vobstermarinesystems/photos/a.479336038838217.1073741828.477898622315292/751918194913332/?type=3&theater

Nick,

TDF has just lost my entire reply, which is a shame.

Second hand doesn't quite count, but the point is, also made above, that there are extra features that will make the difference to someone - I'm not trying to sell you one personally and the JJ is an excellent unit (well done them on price and exchange rate).

We have lengthened the case - it now stands up - extra feature there, cheaper and lighter than a stand. We are looking ata slimline travel frame watch this space, eventually.

I'm happy to agree to differ, and I acknowledge your earlier sentiments, but please be at least prepared for others to want different features in a rebreather and to be prepared to pay for them. For some extras, CO2 and temp stick etc, it's worth it, IF you like that kind of thing. You don't, but I'm not criticising you for that. you're also welcome to come here and see exactly what we do.

There are already more units diving more reliably (pre redhead included). There will be far more when conversions and new unit sales prove how determined we were and how determined we still are to fix this. I take all the points about 'toxic brands' we aren't stupid, we thought carefully about that. The redhead is as new as it can be and still be backwards compatible to existing units.

We are also NOT VR - we employed Yan the service tech after he was made redundant. All other staff at VMS are new.

All the best,

Tim

[Tim Clements]

https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xfp1/v/t1.0-9/12278862_751918194913332_8744700666009493021_n.png ?oh=596ebcfbe896bc81810ac596cc7f3833&oe=56F5A836

[Tim Clements]

That's the 100m PO2 tracking - class leading all the way from 15 litres per min to 72 litres per min, ideal at around 20 litres per min.

[notdeadyet]

II would not like to have to keep monitoring lots of different stuff, I want to concentrate on the dive, not the kit.

There really is not that much to monitor. Manufacturers like to invent things. Ppo2, time, depth. Not really much else to know.

Sent from my GT-I9300 using Tapatalk

[Tim Clements]

If I was to go for a rebreather I'd want one that did everything for me that it could. In the scheme of things £1000 is sod all if it delivers what you want. I would not like to have to keep monitoring lots of different stuff, I want to concentrate on the dive, not the kit.

I did a try dive, with Tim, a few years ago.
I liked the Sentinal green/red light and vibrating mouthpiece. Just swim about until the lights change no need to monitor extra stuff. Result.
What put me off was
1) The reliability reputation.
2) The fact that breathing fairly normally I could empty the counterlung, causing air injection, and then over inflate, causing bubbles, on every breath.

If they've fixed both of these then I might consider it again if I was doing enough diving to make it worthwhile.
At the moment I'm not. :(

I can see the reason for not changing the name if they're trying to get old sentinal users to upgrade.

HI Ron,

Thanks for the reply, we have made some changes to the redhead which will help with the counterlung filling, the rest would be solved with some more personal rigging ( more than can be accomplished on a try dive). I've seen a couple of divers do this and we always get to the bottom of it. The redhead has a modified space for counterlung to expand more consistently.

All the best,

Tim

[Tim Clements]

Er, OK. You've missed the whole recent interest in CO2 haven't you? Lot's of other people are more interested than you are, but that's fine. Enjoy your diving. Tim

[MikeF]

interesting responses from Tim. sounds like there's been some serious review of what did and didn't work before.

what changes have you made that improved the WOB? presumably scrubber design stayed as was so what have you altered to improve the WOB?

[Tim Clements]

https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xlp1/v/t1.0-9/12241636_751918691579949_8228251525902509946_n.png ?oh=83cae7c24847b0dc7c5d88fe147d9fd4&oe=56E8A8A5

Download of a dive on Le Polynesian with new download interface in development - not quite complete yet, but you get the idea of where we are heading. And that at least one Sentinel RedHead has done a 60m dive. It was actually two - I had the other one.

[MikeF]

I'm pretty sure I saw one at 70m earlier this year..

[Tim Clements]

Hi Mike - it's the interior of the head, the flowcone and the counterlung space. Mechanical work of breathing now 0.48 Joules per litre.
Cheers,

Tim

[Digger]

Is anybody else reading this thread, running some numbers, and thinking that an Inspo Classic at £1K with a recent AP service is bargain of the century and more unit than most of us will ever need in a million years?

Personally, if I was VMS, I'd have avoided all association with the Sentinel wherever possible, and launched a replacement head and upgrades under an entirely different brand.

Out of sheer curiosity Tim, what is the RedHead cost if I picked up a secondhand/scrap Sentinel and just wanted the RedHead upgrade? Assume the big numbers earlier in the thread are for a complete unit including the upgrades?

Even when I was regularly CCR diving, years ago, we had Sentinel divers getting out on the boat, and I am yet to see one complete a dive to plan, units just refused to dive or failed in a way that the owner could not resolve and continue with dive plan. A lot might have changed since then before the RedHead, but my experience seems to be a common one even since then, hopefully all that is behind everyone involved.

Digs.

[Tim Clements]

Hi Digger,

Second hand units are selling well across the board, but again, you choose what features you want and pay accordingly. A 1k classic in indeed a workable rebreather, but, doesn't include warnings on scrubber temp (TPM) or CO2.

By contrast, a wired early Sentinel sells for around £1500. These always worked well - the huge majority of sentinel problems came when HP pressure monitoring by the head was done by fibre optic, not a wire. The intention was to reduce flood threats to head, but every time the connection failed, trouble shooting was required, the batteries failed, the remote sender boards failed etc. It was a horror and the first thing we scrapped - back to a wire for us. Hp was most common error, truly frustrating.

The problem with the wired units is that while they may work, there are no spares! The boards and chips are obsolete so a problem means big changes. However, for just over £3k you can stick a redhead almost straight on. I say just over, there are some individual unit variations that vary the price, but that's a good guide. That means you have new PO2 module, new electronics, a backup deco computer you didn't have before and CO2 monitoring.

A second hand 'opticon' machine goes for around £2500-£3000. Maybe, I don't have news on up to date sales so that could vary. These need careful looking at as almost all have been incrementally upgraded. If it was done by VR, it is best to get VMS to look at it and comment on what else we have learned and could suggest. It's a very variable game as these are the roublesome units. The opticon units we have upgraded with new bulkheads and digital wired HP reporting are now diving very well. It is fair to say we learned a great deal looking inside machines that arrived for repair. Often there was evidence of very careless electronics work, but that was also OK as that can be fixed and not repeated.

Why did we stick with Sentinel? I think everyone is missing the point here that we knew a lot of Sentinel divers and felt they deserved not to lose all their cash on an unsupported machine. It was a huge risk, but we have been honest with all our customers. Some have chosen to walk away from upgrades we cannot control, othes have chosen to move forward with upgrades and we fiercely support them and look after them. Some machines have taken a lot of effort to track the problems down, but we have persevered. The result is more Sentinels dive more reliably, there are just a lot fewer out there now, and there were only originally 420 odd.

What we learnt, we put into the RedHead. Again, part of the motivation here was to enable Sentinel divers to move on. We have put a lot of effort in to soften further expense, but it's a diver to choose what it's worth - at least we have provided that choice. Again, we didn't have to. As an aside, we also considered supporting the computers, but it was just a task too much - better to do one thing well and we chose the Sentinel. I'm fine with others thinking that was not savvy, but we did it, it's working and we will work hard to keep that decision working.

We feel we have fixed all the problems. We will almost certainly find some new ones, but they will not be major. We have completed CE testing to the newest, most stringent CE standard 2013, which the old Sentinel would not have passed. So there is some measure of our improvements. We have ISO 9001 and a robust, better QA than VR operated.

That's it really, we are committed to supporting Sentinel divers. We cannot afford to exploit or rip them off, they are our customers. We will create more Sentinel divers - initial repsonses to demos at shows have been very encouraging, from old sentinel divers and new divers looking at all units.

All we ask is that you keep an eye out for successful sentinel dives!

Cheers,

Tim

[nickb]

Er, OK. You've missed the whole recent interest in CO2 haven't you? Lot's of other people are more interested than you are, but that's fine. Enjoy your diving. TimI don't know if that's aimed at me or Stuart.

I haven't 'missed the whole recent interest in CO2' by any means. I'm very much interested in the subject and a reliable solid-state end-tidal CO2 monitor would be great in any rebreather. However, despite Arne Sieber demonstrating such a device at Eurotek 2010, we are still waiting and I suspect will be doing so for some time.

I don't know the details of the CO2 monitor in your unit but I have seen people using the AP Diving version in the Inspo and that is nothing short of a disaster. The technology is nowhere near robust enough in my opinion and I doubt that I'm alone in that.

[Tim Clements]

Hi Nick,

That one was not aimed at you, just got displaced in the thread.

OK - CO2 we could look at various points to measure CO2 - focus mainly either on the levels in the body, or on just after the scrubber. Holy grail - cellular or alveolar for sure as that indicates what is happening the the divers mind and what is actually being produced.

Alternatively, the Sentinel goes for just after scrubber. It's mainly to warn of scrubber failure, either over time, flooding, bad material, poor packing, poor sealing, whatever. The value here shold be virtually nil in normal operation - a rise indicates one of the above. Alarm level is 5mB well before symptoms, but that's OK as we know once a diver (particularly exercising diver) self recognises, the effects can continue to escalate, even if a switch is mode to OC. Interesteingly, there is also some evidence that even switching to O2 can elevate symptoms..... Anyway, most divers would like some early warning of these problems.

The Sentinel sensor works better than the inspo. It is infrared, sending out a beam, bounced back to a receiver off a gold mirror. Anything such as CO2 (being a greenhouse gas) that absorbs the infrared, weakens the beam and this can be measured. Of course, water 'vapour' is also a greenhouse gas.... so the gas needs drying. On the sentinel this works ok with a sponge and some membranes, on the Explorer which also uses the same sensor, it needs some polyacrylamide beads to dry the gas. It doesn't work so well on the inspo, mainly, I'm told, due to moisture.

Why is the inspo damper? The Sentinel does not have a exhale counterlung - the gas remains warmer and therefore moister into the scrubber, this makes the scrubber more efficient and hotter. The additional heat, also retained better by the gas routin back up around the scrubber (er, making the sentinel a bit wider) - this gas acts as an insulator. End result, the water vapour is less like to condense and cause IR sensor problems.

Display is a number - you can see it go up, and down, thus helping the diver make better decisions.

Cheers,

Tim

[Tim Clements]

I should also say, that in over 500 Sentinel hours, I have been able to trust it greatly - sure there have been some creeping readings, but I have always found the reason and it was only once the sensor - more often my mistake that a false positive.

[nickb]

If I was to go for a rebreather I'd want one that did everything for me that it could. In the scheme of things £1000 is sod all if it delivers what you want. I would not like to have to keep monitoring lots of different stuff, I want to concentrate on the dive, not the kit.If your attitude to rebreather diving is 'Jesus, take the wheel', you're probably better-off sticking with OC.

[Tim Clements]

If your attitude to rebreather diving is 'Jesus, take the wheel', you're probably better-off sticking with OC.

Ha ha, that's not quite how it's meant to work!

The green light is a summary that what you told the rebreather you wanted, is still what you are getting. Readings creep off, HP slow leak develops etc the solid green HUD changes to a flashing blue green. Look at your handset, fix the problem. Ignore the blue green, eventually your PO2 will be dangerous etc and the ANGRY RED led will flash.

In normal operation, this works as an early warning system. You should still check handsets not less than every 5 mins to 'police the police'.

This system was designied initially to prevent divers becoming hypoxic due to the O2 being turned off when they dived in - remember the Inspo circa 1999/2000 - all those preventable deaths? well that's the root of the concept, extended to cover all other variables. It's a valid choice and a different way opf thinking, but like all choices you don't have to choose it.

It only works if it the sensor readings are reliable. They are now.

Cheers,

Tim

[Ron MacRae]

If your attitude to rebreather diving is 'Jesus, take the wheel', you're probably better-off sticking with OC.

The whole point of automation is to remove all the boring crap and leave me to look at the scenery.
If I have to sit and stare at readouts from different cells erc that's a waste of my time.
Hopefully the automation should tell me as soon as a problem occurs and not wait for me to look when I could be distracted by fishies.
With OC it's quite simple. If I can breath and I've not exceeded my dive time I'm ok.
I don't need more complications in my life.

Depends if you trust hardware or yourself more....

[Tim Clements]

The whole point of automation is to remove all the boring crap and leave me to look at the scenery.
If I have to sit and stare at readouts from different cells erc that's a waste of my time.
Hopefully the automation should tell me as soon as a problem occurs and not wait for me to look when I could be distracted by fishies.
With OC it's quite simple. If I can breath and I've not exceeded my dive time I'm ok.
I don't need more complications in my life.

Depends if you trust hardware or yourself more....

OK, CCR is more complicated that OC, there are benefits, but more to go wrong with rebreathing, on any unit. The choice you have is to do this yourself, look at two gauges, set of cells, taste the gas for CO2, work out in your head what they should be, then get back to the scenery. The time everyone needs to change to CCR builds this into a new dive pattern that should do two things - help you enjoy your dive and keep you safe.

Some people like manual everything, some people like solenoids, but not HP, the Sentinel offers you a sensor for everything and will tell you as soon as those readings are off optimal. However, more sensors means more complexity and we're right back to the marmite question for the sentinel concept. How do you know if the sensors are correct? The new dive habit you build for the sentinel includes confirming the system is working, usually with a glance from time to time. It's not time consuming if you learn properly and practice, just like anything. When you have this habit, you can spend more time diving confidently and less time driving a CCR.

Reliability was an issue - that is no longer the case - great improvements have been made and we're committed to keeping on this track to make the effort / benefit balance of the Sentinel work for divers.

Tim

[notdeadyet]

This thread sounds oh so familiar. Red Head might've been an unfortunate name choice.

Sent from my GT-I9300 using Tapatalk

[jturner]

This thread sounds oh so familiar. Red Head might've been an unfortunate name choice.

The difference is that this one actually exists!

[Tim Clements]

Green head didn't quite have the same ring to it!

The concept is a choice. It's not for everyone, sure. Some people don't need it, some don't like it, some like OC more. Each to their own, but for those that like the Sentinel concept it works far better than before.

I look forward to seeing more Sentinel divers out there. I think we're done here for now, but I'm happy to answer any questions as a pm or on tim@vobster.com, or show anyone round VMS.


Tim

[notdeadyet]

it works far better than before.


That is such a good marketing slogan :)

Good luck with it. I cant see it being much of a seller though.

Sent from my GT-I9300 using Tapatalk

[Baron015]

That wasn't enough for you to stick with it though, was it mate?

Are you considering reverting back?

Yes, if the Red Head had been available at the time I switched, I would probably still be on the Sentinel today. I am happy to report I was one of the alleged few who almost never missed a dive because of the Sentinel (wired model) not working, although there were frequently niggling issues.

And in reality the other units break down too. E.g. right now on my JJ the voltage monitoring circuit in my OBOE board is not working and the head has to go back to Denmark when I have a gap in diving. I am just carrying on diving with the failure.

A mutual friend who lost loads of days in Plymouth with Sentinel issues (Opticon model) swapped to a JJ (analogue model), now he has had complete PPO2 control failure in Truk and had to buy a new JJ head and get it sent out.

The only time I ever saw a Mk 15,5 in the flesh, it was not working and the owner missed the dive.

Most people I know with Inspo's are swearing at them.

Etc.....

[MikeF]

did he have to buy a new head or was it a convenient excuse to buy a new dive can head? :)

surely no PPO2 control on the JJ just means dive manual whereas no PPO2 control on the sentinel was a no dive as you couldn't complete pre dive sequence?

[Baron015]

did he have to buy a new head or was it a convenient excuse to buy a new dive can head? :)

surely no PPO2 control on the JJ just means dive manual whereas no PPO2 control on the sentinel was a no dive as you couldn't complete pre dive sequence?

The PP02 readings were just wild and all three cells reading differently way out on O2 at 6m. So I don't think diving manual was an option he was comfortable with. But there was probably a certain attraction to getting a DiveCAN head anyway, you are right.

Let's not forget our dear CCR friend from your neck of the woods who bought a cheap £1,000 Inspo Classic to learn with, had nothing but trouble with it, had to dive OC in Bikini (think of the gas bill!!) because said Inspo Classic let him down irreparably, and ended up buying a 2nd hand JJ.

There is a similar story for every make of rebreather not just the Sentinels.

[windymiller]

I have one of the original hardwired sentinels just sat in my garage...works apart from the TPM... I was tempted to upgrade but at about £3500 I was quoted that didn't even include a service...unfortunately from what I've seen VMS has inherited the VR price list as well as the sentinel! I've never heard of a sentinel service being under £700..

That's why I went back to an inspo, last 2 services under a 100 quid and even when I had the HUS upgrade that price included a service!

Shame, I used to like my sentinel

Sent from my Nexus 5 using Tapatalk

[flyingfisheye]

PPO2 control on the sentinel was a no dive as you couldn't complete pre dive sequence?

I believe that not being able to complete the pre dive sequence is not a reason not to dive, if you know the reason for the failure. once in the water the unit will functions per it should. it will log that the sequence was not completed but will let you carry on.

[Barrygoss]

did he have to buy a new head or was it a convenient excuse to buy a new dive can head? :)

surely no PPO2 control on the JJ just means dive manual whereas no PPO2 control on the sentinel was a no dive as you couldn't complete pre dive sequence?

As he's been trying to flog his JJ to me since May ;) I think he jumped, rather than was pushed :D

B


Sent from my iPad using Tapatalk

[flyingfisheye]

There is a similar story for every make of rebreather not just the Sentinels.

We all know of people who have possible binned a dive because of their unit, how many AP units had cell issues for 2 years? I had a mate who was diving on an inspo with 50 minutes of stops to do, the unit turned it's self off and he restarted it, it came back on with all the stops gone. AP said some control issue cost £1000 plus for new head. Another 2 mates sent their Inspo back to AP both had cracked heads and needed a fairly chunky bit of change to keep their units going too.

[edward]

Bloody hell, think I'll stick with OC for now:)

[gobfish1]

The PP02 readings were just wild and all three cells reading differently way out on O2 at 6m. So I don't think diving manual was an option he was comfortable with. But there was probably a certain attraction to getting a DiveCAN head anyway, you are right.

Let's not forget our dear CCR friend from your neck of the woods who bought a cheap £1,000 Inspo Classic to learn with, had nothing but trouble with it, had to dive OC in Bikini (think of the gas bill!!) because said Inspo Classic let him down irreparably, and ended up buying a 2nd hand JJ.

There is a similar story for every make of rebreather not just the Sentinels.

i use a 1000 quid unit , and a few add ons as long as i have 3 good cell and it hold s gas i can dive it ,
unit tuened on or off , no mater ,

[gobfish1]

i use a 1000 quid unit , and a few add ons as long as i have 3 good cell and it hold s gas i can dive it ,
unit turned on or off , no mater ,

why would you need H to dive bikini , so i pay 8k for a dive trip and then worry about a few 100 quid gas bill lol

i could buy a 2nd hand head for next to feek all and be worry free and still be under 3k all in

[Capt Morgan]

why would you need H to dive bikini , so i pay 8k for a dive trip and then worry about a few 100 quid gas bill lol


Same reason he got a JJ, GUE :)

[nickb]

Same reason he got a JJ, GUE :)Are we talking about the same person?

[notdeadyet]

i use a 1000 quid unit , and a few add ons as long as i have 3 good cell and it hold s gas i can dive it ,
unit tuened on or off , no mater ,

The more shite you have the more likely it is to go wrong. I missed one dive on my KISS in 4 years and that was me leaving an o-ring out.

[gobfish1]

http://www.ebay.com/itm/AP-Diving-Inspiration-Evlolution-Vision-Rebreather-HUS-Lithium-Battery-Trimix-/301712823724?nma=true&si=OKRLqUtybA1FInZZnPqF2ouQ8yw%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

all singing and still quids in , if you like the all singing

[Capt Morgan]

Are we talking about the same person?

No idea who it was, well if I had to take a guess I might not be far wrong,
but it was just a bit of a joke about diving trimix in Bikini and buying a JJ.
Would he be in this video with MikeF ?
https://vimeo.com/52449112

[gobfish1]

No idea who it was, well if I had to take a guess I might not be far wrong,
but it was just a bit of a joke about diving trimix in Bikini and buying a JJ.
Would he be in this video with MikeF ?
https://vimeo.com/52449112

Santa Maria must have closed for the day , lol 50k of kit to stick a team on a noddy wreck , strob and all

[MikeF]

wow that's a blast from the past. seeing someone swim by who is no longer here makes you think.

but D was still OC in those days and the inspo that died in Bikini is on my back. strangely it seemed to work fine for the three years I owned it :)

[MikeF]

Santa Maria must have closed for the day , lol 50k of kit to stick a team on a noddy wreck , strob and all

did the SM on the way out and some of the lads had never dived the Lochgarry so we jumped in on the way home after getting blown out. but yes a bit of overkill on the kit front for a shallow bimble :)

[Capt Morgan]

I'd say it's the most divers I've ever seen on that wreck at one time.
Kind of makes me want to dive it again just to see what it's like now

[Pat Coughlan]

I was one of the early adopters of the Sentinel (#12) and dived it with no problems for 5 years until one of the batteries died, thats where the fun started. At that time Mr Gurr had disappeared over the hill and left a lot of customers with a bitter taste in their mouths. This was my first dealing with VMS (Martin TY and Jan), I thought it was going to be a run of the mill battery change test unit and back diving but no the O2 cable had a crack in the potting and couldn't be replaced as spares were no longer being manufactured (prior to VMS taking over) and the main board as corroded, to be fair they tried to repair the cable gland but were unsuccessful,

I was faced with an optocon upgrade and my initial reaction scrap the unit because of the optocon horror stories that were out there. I got a phone call from Martin who to be fair took the time to explain the problems he had been left with when he took over for Vr and the bad rep he was trying to fix and accepted that customers were getting a shit deal because of Vr and that he wanted to work with customers. I did upgrade at a reasonable cost and still dive the unit.

The guys at VMS they are a decent bunch to deal with and are fighting an up hill battle to undo what had gone before them. Im sure the Red Head works well and looks well engineered. Did I go for the Red Head up grade, well no the reason being when I bought the Sentinel the JJ wasn't about and the JJ lends itself readily to the configuration I dive with:rofl:

Like all units there are pros and cons to it and you have to find a unit that suits you and your style of diving. If you have a diver and electronics and you want a fook up .....just add water!

Cheers Pat

[Hot Totty]

Well just warn everyone I'm going to bite the bullet and place an order this weekend, unit of choice Redbare! Multiple reasons but mostly when I had the opportunity to be involved in the CE evaluation it felt like meeting up with an old friend that had somehow managed to grow up and eliminate all the irritating character flaws. I then saw the latest incarnation at the dive show which kind of cemented my desire for it, tying that desire in with a reason to dive beyond recreational depths just closed the loop (bad pun) for me. So look out for a shiny redbare driven by a muppet (relearning all those skills taught 4 plus years ago) off the Dorset coast in the coming season :)

[Hot Totty]

Deposit paid - no going back now :) . Although it appears the head moulding (normally red) may be black due to a world shortage of red plastic dye or something;) . Suppose it'll be called a blackhead now :D. So keep an eye out and see if you can 'spot' me diving somewhere;)

[Vanny]

Good luck , enjoy !

[gpj]

Deposit paid - no going back now :) . Although it appears the head moulding (normally red) may be black due to a world shortage of red plastic dye or something;) . Suppose it'll be called a blackhead now :D. So keep an eye out and see if you can 'spot' me diving somewhere;)

schwarzkopf? :rofl:

[Hot Totty]

schwarzkopf? :rofl:

reference to hair products or cookies - confused ;)

[gpj]

reference to hair products or cookies - confused ;)

German translation.

[jamesp]

Deposit paid - no going back now :) . Although it appears the head moulding (normally red) may be black due to a world shortage of red plastic dye or something;) . Suppose it'll be called a blackhead now :D. So keep an eye out and see if you can 'spot' me diving somewhere;)

What material?, I deal with two companies that manufacture master batch for plastic moulding.

[Hot Totty]

What material?, I deal with two companies that manufacture master batch for plastic moulding.

No idea, vms's gig and tbf I'm not especially fussed, just thought the idea of diving a black head funny ;)

[jamesp]

No idea, vms's gig and tbf I'm not especially fussed, just thought the idea of diving a black head funny ;)
Could be messy if it pops.