Hello and welcome to our community! Is this your first visit?
Register
Page 1 of 3 123 LastLast
Results 1 to 10 of 21
  1. #1
    Established TDF Member
    Join Date
    Apr 2017
    Location
    Glossop
    Posts
    868
    Likes (Given)
    297
    Likes (Received)
    233

    SCR as a survival option

    I realise this can be a divisive subject and have read plenty on other forums but wouldn't mind debating it with the great and the good on here.

    I am moving into OH next year where I believe with a relatively stable depth profile SCR could be an option.

    It was only dealt with minimally on my MOD1 and am thinking Winter will be an option to practise further.

    In essence I think the main failure modes it could be used in are loss of o2 or loss of displays.

    Cycles seem to range from 2 to 4.

    Well aware of the possible strain on lungs if pulling past a stiff ADV but could use BOV to inject.

    Just interested in any/all views on topic TBH.

  2. #2
    Established TDF Member
    Join Date
    Jan 2013
    Posts
    1,390
    Likes (Given)
    133
    Likes (Received)
    538
    Carry enough OC - have this as a back up . Try it and you'll see what I mean

  3. #3
    TDF Member
    Join Date
    Sep 2017
    Location
    Chippenham
    Posts
    200
    Likes (Given)
    10
    Likes (Received)
    52
    Quote Originally Posted by JonG View Post
    I realise this can be a divisive subject and have read plenty on other forums but wouldn't mind debating it with the great and the good on here.

    I am moving into OH next year where I believe with a relatively stable depth profile SCR could be an option.

    It was only dealt with minimally on my MOD1 and am thinking Winter will be an option to practise further.

    In essence I think the main failure modes it could be used in are loss of o2 or loss of displays.

    Cycles seem to range from 2 to 4.

    Well aware of the possible strain on lungs if pulling past a stiff ADV but could use BOV to inject.

    Just interested in any/all views on topic TBH.
    Sorry Jon I may be missing something here but why not just use MAV rather than repeatedly use BOV/ADV?

  4. #4
    Established TDF Member
    Join Date
    Apr 2017
    Location
    Glossop
    Posts
    868
    Likes (Given)
    297
    Likes (Received)
    233
    Early KISS had no option for offboard MAV unfortunately

    Plus u might want to turn your 3 into a 6 or 9 and preserve offboard, assuming MAV was to offboard
    Last edited by JonG; 06-12-2018 at 06:31 PM.

  5. #5
    TDF Member
    Join Date
    Oct 2013
    Location
    Widnes
    Posts
    162
    Likes (Given)
    26
    Likes (Received)
    23
    Personally depends on the situation, I do not do OH yet so my nearest would be a return to shot dive vs solo ascent under DSMB and potentially being a long way away from everyone else. If an incident happened and my breathing rate was relatively stable I would attempt SCR to return to the shot. If an incident happened and it wasn't stable I'd just head up and use my bailout as normal. I've only used SCR on courses and honestly I do not practice it (my bad) but from the short time on courses I would not attempt it with any significant changes in depth, ppO2 drops to fast for my liking. If push comes to shove I'd rather skip deep stops than attempt SCR.

  6. #6
    TDF Member
    Join Date
    Sep 2017
    Location
    Chippenham
    Posts
    200
    Likes (Given)
    10
    Likes (Received)
    52
    Quote Originally Posted by JonG View Post
    Early KISS had no option for offboard MAV unfortunately

    Plus u might want to turn your 3 into a 6 or 9 and preserve offboard
    Ah I see, so your only option is breathing it in through the BOV. For me there would need to be a delay of some kind to go SCR if i needed to go to the lengths of breathing in through the BOV.

    Adequate bailout gets you home, so unless you are entangled, lost, off line, lost buddy etc.

    With a MAV I would err towards SCR as it's less taskloading. But if in a straightforward OH without significant depth change, squeeze, etc then I guess the task loading of SCR wouldn't be too great although it does seem that concentrating on that is likely to delay your egress to fair degree based on you needing to breath dil in.

  7. #7
    Established TDF Member
    Join Date
    Apr 2017
    Location
    Glossop
    Posts
    868
    Likes (Given)
    297
    Likes (Received)
    233
    Quote Originally Posted by dunny View Post
    I do not do OH yet.
    I am doing it to gain access to the north Welsh flooded slate mines Dunny and the Chert Mines at Bakewell.

  8. #8
    Established TDF Member
    Join Date
    Apr 2017
    Location
    Glossop
    Posts
    868
    Likes (Given)
    297
    Likes (Received)
    233
    I have always been pretty anti but the American cavers seem to be quite keen so want to do due diligence.

  9. #9
    GUE Tech and Cave Instructor johnkendall's Avatar
    Join Date
    Dec 2012
    Location
    Cambridge
    Posts
    663
    Likes (Given)
    79
    Likes (Received)
    394
    Quote Originally Posted by graham_hk View Post
    Carry enough OC - have this as a back up . Try it and you'll see what I mean
    This! Even on Dives with multiple hours at depth in a cave, it's still possible to carry the required OC bailout. F#@king about trying to run SCR in a cave is exactly when you'll make a navigational error and then drown horribly. caves are no place for internet diving techniques, keep it simple, take enough OC gas.

    HTH
    John

    Sent from my Pixel 2 using Tapatalk
    John Kendall
    GUE Instructor Trainer, Tech and Cave Instructor www.johnkendall.com
    www.divinganalysers.com - Nitrox, Trimix and Single Gas Analysers
    www.santi-store.co.uk - Santi Drysuits, Undersuits and Accessories

  10. #10
    Established TDF Member
    Join Date
    Jan 2013
    Location
    East Midlands
    Posts
    2,957
    Likes (Given)
    862
    Likes (Received)
    1156
    Blog Entries
    2
    Quote Originally Posted by johnkendall View Post
    ... and then drown horribly.
    Not even just drown - it will the worse than that! Fatally killed to death.
    I'm not a cavey person but I have to say from the few times I've tried it for more than a few minutes, it is an utter balls-ache to do continuously whilst doing other things, and unless I had no other choice (eg CCR has failed and bailout has all leaked away so it was SCR or death), I'd rather not.
    YMMV and all that. I don't think I count as the great or good, so feel free to ignore me!


 
Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •