Rough safety stop

[Frosty]

We did a two tank dive yesterday. First dive was a textbook 50 minute play at around the 60 foot mark.
A good surface interval and the second dive was planned as a circuit of a reef. Fairly strong current so the legs got a workout going one way but over the end and back the current worked for us and we gently ascended to our safety stop.
This is where things got a bit tricky. At the safety stop the current had gone strange. It was like being at the beach with short sharp waves slamming one way then quickly reversing and slamming back the other way.
We tried hanging mid water and got tumbled around. So we hung of the solid rock but still took a reasonable pounding waiting out our time.

So in that situation what would you have done?

 

[Blackwood]

My first choice is dealing with it in midwater. Failing that, I'd blow off a safety stop rather than risk getting battered on the rocks.

 

[Bubbletrubble]

So in that situation what would you have done?

It sounds like you encountered fairly strong surge. Anything can happen in the ocean.
If the back-and-forth water movement was annoying/dangerous, I would have just skipped the safety stop and terminated the dive.

Safety stops are optional.
Safety stops are generally a good idea...unless doing them presents greater risk to the diver(s).
For some reason, many basic OW students exit class with the mentality that a safety stop should be conducted on every dive -- no exceptions...ever. They think that skipping a safety stop guarantees or greatly increases the chances of a DCI-related incident. This attitude can actually be rather dangerous. I've heard of some divers choosing to go OOA rather than forego a safety stop. (Don't even get me started on the lack of attention to gas management.)

When in doubt, end the dive in an expeditious manner that minimizes risk to you and your buddy.

Whenever you dive a site that can feature current, you have to be prepared for unpredictable water movement. Plan your dive conservatively with respect to nitrogen-loading and gas management. Seek out "shelter" from the current behind rocky structures. If you're kicking against the current, expect significantly increased gas consumption. Monitor yourself and your buddy for signs of exhaustion. Hang onto some firmly planted structure if you're getting tired and you need to hold your position. Be committed to sticking with your buddy. Have contingency plans if you get swept out to sea. Know your emergency action plan in case you get pummeled into nearby rocks.

 

[Frosty]

BT nahh I'm not hooked up on the safety stop thing but heck one day its gonna maybee be a deco stop and the same issue so why not work out the best strategy now rather than waiting.

 

[Rhone Man]

Safety stop is a precaution. It isn't worth getting injured for.

 

[Bubbletrubble]

BT nahh I'm not hooked up on the safety stop thing but heck one day its gonna maybee be a deco stop and the same issue so why not work out the best strategy now rather than waiting.

In principle, those are two completely different situations.
There is a significant difference between conducting an optional safety stop and fulfilling a mandatory decompression obligation.
Omission of the latter carries with it significantly higher DCS risk.

When the day comes that you intentionally encounter a mandatory deco stop, you will have already received the training and experience necessary to handle it properly.

 

[Frosty]

HMM--I did actually think that a nice slow ascent rather than a safety stop would be a better option.

 

[Blackwood]

Part of diving with a ceiling (deco or hard) is thinking on your feet, so to speak. How you react is a function of your thought process, your training, and the environment.

One option may have putting some distance between yourself and the rocks, perhaps shooting a bag. If there is heavy current taking you into boat traffic or something similar, maybe hanging onto the rocks is the right option.

...

But before you descend and incur deco, you should recognize and accept the fact that situations may develop in which blowing off deco is preferable to satisfying it.

 

[TSandM]

Okay, I think it's great that you are thinking ahead, and figuring out how to handle this kind of situation when you have a deco obligation and CAN'T blow the stop.

What was the problem? Did you have an upline you were trying to stay on? Could you not hold your depth? Were you getting beaten into structure?

If you are in surge, the key is to get away from the structure, and let the surge push you back and forth. Surge won't hurt you, and it's EASY to maintain general position, if you notice which direction you are tending to move, and use your fins when you are moving the other direction. Surge won't take you away from the upline, although you may oscillate to the ends of the visibility. If the viz is so poor that you can't trust that you won't lose the upline, you can either connect yourself to it, through hands or a jon line, or shoot a bag and hope that the boat can pick you up.

Current doesn't shift that fast, and mild current can be dealt with by facing the team into it, and just swimming constantly to stay in contact with the upline. (If there is no upline, then there is no reason to CARE what the current is doing; shoot a bag and drift.) Very strong current may require you hang onto the upline, if you don't have a scooter; I don't do staged decompression dives (or any deep dives) in areas where strong current is a possibility, without a scooter for insurance.

Swell and chop can be problematic, if you are ascending an anchor line. A big boat can yank an anchor line up and down an amazing amount in swell -- if you fixate on the line as a visual reference, your ability to hold a stop will be poor. In that case, you have to use the particles in the water, or your depth gauge as your reference, and merely glance at the line from time to time, to make sure you are staying within visual range of it. We did several dives like this on our recent Channel Islands trip -- it can be disorienting, to be sure. Holding onto the line when the boat is dragging it up and down can be dangerous -- you can even embolize, if you are unaware of being yanked up, and hold your breath. Far better to maintain a steady stop without holding on.

 

[scubadiveilat]

How deep was the second dive? You may not have had to do a safety stop.

A safety stop does not require you to stay a stop exactly. If possible sure otherwise go with the flow at the depth of 5m approx. You can dive towards the return point while maintaining the 5m mark. Instead of being precisely on 5m depth.

It's good to know the dive site as well. As you can prepare for rough currents or other issues. Are there any rocks, object, life line or other thing to hold on to while doing the safety stop.

It's a matter of creativity at a glance. The best you is what you can....


Have fun diving and enjoy....