CCR Weighting/Trim

[JonG]

Whilst the amount of weight any one diver will require is subjective is there any commonality in terms of better places to carry weight to trim a CCR rig or is it unlikely that it will be required in the majority of cases.

Initially I will be diving a KISS classic with 3 litre dumpy Heisers (valves down), 2l aluminium suit cyl and a 7l aluminium stage. Membrane dry suit, negative fins.

Just not sure where weight is best added if required e.g. cam bands, tube lead etc.

[Hot Totty]

I suspect it varies from unit to unit, my old disco box needed it all as high as I could get it - the new VMS version arriving Jan no idea, but it'll be fun working it out

[Capt Morgan]

Any weight is best added as high as possible
to help with trim. Before I fitted a stainless
case to my KISS I used a 6lb "top hat" that
fitted on the brass scrubber screw.

[nigel hewitt]

When I bought rebreather number four, my back counterlung Inspo, I did a couple of pool sessions in the full drysuit, hood, gloves, can lamp, the works and trimmed out until I was neutral in the shallow end and trimmed out dead level (actually neutral trim so I just stayed where I was put) and that involved 4Kgs on top of the scrubber, just behind my neck. Then I weighed everything on a digital scale dangling in the water on a bit of string so I know what I need to do to fix for taking it/leaving it. I was careful to inflate the suit when level and then let it bubble off so by just rocking left or right I could tweak it to be a bit high or a bit low.

I have to say it was the best trick ever. I plan a dive, plan the kit, plan the weight allowing for 2.7% extra for seawater on total weight and it just works. Trimming for neutral does mean I am swimming down the shot rather than just sinking but the auto dump really is auto now and it is virtually buoyancy control by will power alone. Green water ascents just work.

[Vanny]

Yeah I'd say it'll vary unit to unit, but my inspo Carrys the weight high to get flat. The only common theme from reading various threads is you might find you'll favour lighter/buoyant fins. I've stuck with my SP jets as I just luv em but I'd benefit from switching to something more positive.

[JonG]

Any weight is best added as high as possible
to help with trim. Before I fitted a stainless
case to my KISS I used a 6lb "top hat" that
fitted on the brass scrubber screw.

Where did you get the top hat from Morgan?

[JonG]

Given that the consensus is to get the weight high on the unit which makes sense given the lungs/counter lungs and scrubber cavity is at that point, what different methods are employed to achieve this. Obviously these will be unit/rig specific but interested to see what the options are in case I can employ them on my set up.

[Hot Totty]

Zip ties, or weight pouches zip tied to case.

[Capt Morgan]

Where did you get the top hat from Morgan?

Mine is cast lead and came with my unit but I have seen some people have cut 10mm stainless and fitted it, that way you can fit more than one of needed.

[Vanny]

The AP has trim pockets in the top of the wing, very handy. In the plastic box I stuffed a shot bag on top of the head as well. I guess weight pouches could be your friend , easy to attach to the cylinders or secure on to the unit somewhere.

[gobfish1]

As others have said top of unit some place , also seen a few divers with lead strapped to top of cylinders

[Mark Chase]

I used the stainless steel CL case on my kiss and needed no lead for UK dry suit diving and it trimmed out great with dumpies.
Cave diving id have the Ali box and I needed 2KG strapped to the top of the 3ltr tins. I didn't need the lead but needed it to trim out


With dumpies Id keep the tanks high as poss same with standards and id strap the 1Kg lead blocks under the tank

See below


report16 by markchase8, on Flickr

IMG_2855 by markchase8, on Flickr

[EngelenD]

And I changed from jetfins to OMS slipstream and then to deep6 fins wich are even lighter then the slipstreams


Verzonden vanaf mijn iPhone met Tapatalk

[thetrickster]

Key things for me

Lightweight Fins - I have F2's (I think there are probably better ones, but I like them and good for travel)
If you have externally mounted cylinders (on say a travel frame) - I've got 2 cambands from APDiving that fit 3ltr cylinders and I've got 2 weight pockets, and have 2 2kg's strapped to the top of the cylinders, this as help immensely.

[dunny]

You can also get trim pockets which attach to cylinders to help get the weight higher up if required.