Managing Task Loading - a matter of priorities

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This happened to me recently in the South Pacific, no current, but poor visibility. We missed the upline as it was not on the wreck but in the sand off the wreck. Since there was no current, we blew the bag at 30', did out deco (about 25 minutes) and then surfaced. Not too far away from the boat. The boat knew where we were and was not concerned that we were not on the upline.

But if there is current, or suspected surface chop, or if you are on a rebreather, the boat is not going to track your bubbles. Then if you blow the bag at 30' or even 60' you may be too far away for the boat to see and at best you have set up a rescue situation. So with a current I would always blow the bag from the wreck, particularly with a decompression obligation.

Jerry
 
Usually slackwater is over by the end of the dive when I am ascending so most of my safety stops are done drifting midwater in a current so I am curious about the need to launch an SMB at the bottom? Especially if I had a buddy that was a bit stressed or was close to NDL. I would put that last, ascend with my buddy a bit so he calmed down and then worry about the SMB.

Someone mentioned that a captain mentioned it is helpful for them if you launch it immediately, however on dive briefs the captains were I dive request that we put up an SMB during a safety stop or deco stop unless we make it back to the shot line (though usually this is quite hard if slack water is over). So again, that is different to people's experiences here so was wondering about that...
Obviously do whatever the captain suggests in his briefing.

Whenever Im diving in strong or unpredictable currents my first priority (after making sure that I and my buddy both have enough gas to breathe and are together) is to send up an SMB (if I miss the upline). Drifting, lost at sea, is an experience Id very much like to avoid and the sooner you put up an SMB the better. I would go so far as to say that Id rather overstay my NDL by a minute or two (even if I dont have the gas to complete the extra stops) to put up an SMB right away.

Obviously all this is situation dependent...ymmv
 
Thank you Diver0001
... another great post, and another great thread

(saving this for future reference)
 
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Yes, this is one of my all-time favorite threads.
 
I tend to come down on the ounce of prevention is worth a pound of cure side of the fence. I am also heavily influenced by my experience with a sadistic instrument flight instreuctor who revelled in task loading excercises. Pre-planning and mentally staying well ahead of where you are in the dive goes a long way toward minimizing task loading and is way moreeffective than any reactive approach.

In that regard task load management starts with :

1. Don't get lost in the first place. Keep track of where you are on the wreck in relation to the upline and in relation to your gas supply. Conduct the dive so that you end near the upline. If the viz is poor or your situational awareness, spatial or navigational skills are weak, run a reel from a point near the ascent line (never tie to the anchor or ascent line.)

2. Plan ahead. Arrive at the area where the upline is supposed to be with enough gas above your reserve left to give you a few minutes to problem solve in the event the line is not there. Make a mental note of any other uplines you see during the dive and make a pre-dive note whether other boats were on site before or after your boat arrived.

3. Pre-consider what you would do in a given situation and carry out that plan. I am a big believer in shooting a bag on the bottom and tying into the wreck in all situations except those where a drifting deco is the plan for the whole boat. You won't get lost and if the boat had to pull the hook the captain has the numbers for the wreck and knows exactly where to find you. Consequently, if I navigate back to where the hook was tied in and it is gone, the next steps are a no brainer - tie in, shoot a bag and ascend.

4. Shooting the bag from the bottom also eliminates the shooting the bag mid water while trying to maintain buoyancy and contact with the buddy issues and in that regard minimizes task loading. Drift isssues aside, shooting the bag on the bottom may in the end be more efficient than trying to do it mid water even with the higher gas consumption unless you practice mid water deployments a lot.

5. Deeper water should automatically mean a greater reserve to offset the potential for greater gas consumption and or additional deco in the event you have to delay a few minutes on the bottom to deploy a bag or deal with an emergency. Having the gas (and the time) to deal with a problem gives you lots more options, reduces stress and reduces task loading.
 
Generally, I agree with the "head up when low on gas" thinking, but what if you knew there was more gas waiting somewhere along the upline (like other divers and/or regs or tanks hanging from the dive boat)? Would it make sense to spend a little bit of time trying to find/get back to the upline, or would it be better to still send up the SMB?

In a problematic situation like this, if I used what little gas I had left looking for more instead of ascending with what I have, I'd pretty much end up going into a panic when I'm unable to find it. It's a gamble that I personally wouldn't want to take.
 
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