What to do in this type of situation?
On a recent lobster dive I happened to capture my computer readings and gas pressure readings for the end of my dive. I pushed the no-deco limits to catch a lobster, wound the “clock” down to ZERO minutes leaving me ZERO No Deco Time. Then, as soon as I started my ascent, the computer kicked me into a REQUIRED Decompression Dive.
My gas pressure at this time is about 500 psi (in a 108 cu-ft, steel tank).
Certainly it is NOT recommended or safe for recreational divers to push the limits or go into deco and they probably should be saving more air for the ascent as well. Many people are taught the simplistic rule of: be on the boat with 500 psi – which may be inadequate.
The reason I made a video of the ascent is to demonstrate that this is NOT the time to panic or get really worried, or rush your ascent, or kick up hard or begin to breathe fast or get overly stressed out.
We have many examples of divers who have never seen their computer in deco and once it happens they kinda freak out and rush to the surface – breathing like a freight train. Sometimes I think they feel their goal is to get on the boat with as close to 500 psi as possible – so the faster they rush to the surface the less “trouble they are going to be in”. This is NOT the way to handle such a situation. (Most instructors would say that the best way to handle this situation is to avoid it, but that is not the point).
This video demonstrates what I do (or did on this occasion) in this situation. Keep in mind that the deco penalty is as small as it can be (only one minute), but many people would be very concerned by “being in true DECO” and also having just 500 psi at around 100 ft depth.
Instead of exerting myself, you can hear me pop the inflator and get just slightly buoyant so I can drift slowly upward with zero kicking. I slow my breathing and RELAX. I go up SLOW, I check my depth frequently and carefully monitor my ascent rate.
This video is in real time (except for the pauses during the console reading). By the time I reach a depth of about 44 ft (I think it is) – Wow.. my deco penalty is gone - and I have many minutes of no deco time back on my computer.
This is not surprising to a good percentage of experienced divers.. come up a little slower than the maximum ascent rate, relax and your deco time will “clear itself” before you even get close to the decompression ceiling depth. For them, the video will be trivial and boring (maybe that is the point of the video).
My objective in posting this is NOT to advocate or recommend that any recreational diver put themselves in deco and they certainly should preserve a safe volume of gas for their ascent (and enough to share with a buddy). My goal is to provide a simple example that if you (unintentionally) go a little into deco, it is possible to make an ascent using a modest amount of gas, do it reasonably safely and this is NOT THE TIME TO RUSH TO THE SURFACE.
For this dive, I was alone – so I had no need to reserve air for a buddy, I had an independent bail out bottle (a pony bottle) as a back up and I was not diving in an aggressive or reckless manner. I continued a slow ascent and completed an additional safety stop on this dive (as I do on almost every dive) and exited the water with a few hundred psi remaining (and a full pony bottle).
Making an ascent from this depth while sharing air with a panicked buddy and having to exert yourself would result in air consumption rates that would be 5 or 10 times higher than shown in this video, so please don’t interpret this as a suggestion that people should be starting their ascents from 100 ft with 500 psi! The objective is to show what it might look like if you over-stay “your welcome” for a few moments and how it might be handled – even if you have not reserved a whole lot of air.
Since the intended audience is inexperienced recreational divers, it is also very important to remind them that if they continue to remain at depth (once the computer kicks into deco), the penalties (i.e., true deco time) will accrue quickly and a 1 minute deco stop can turn into a 5 or 10 minute stop faster than you can catch a lobster… Especially if you are silly enough to do this on the 3rd dive of the day. This can be a serious or life threatening situation if you don’t have the gas and skills to deal with decompression.
Maybe others will find the topic useful?
