Ten Foot/3 Metre Stops in Heavy Swells?

[smoritz0370]

How did current come into this conversation? The dive in question is in Lake Ontario. As such the period of the waves is shorter than what you would expect in the ocean. This means your bottom timer will cycle through the change of pressure above you more frequently. You should plan to stay a little lower if doing deco to try to avoid getting caught up in the swells. Stay near the line and watch it go up and down with the waves. Don't grab on, if you have good trim it shouldn't be much of a problem to maintain position. No Jon line should be required. Don't substitute equipment for skill.

Planning your last stop at 20' is a good idea given these conditions.

 

[Gilldiver]

For starters, I'm not DIR.

A couple things come to mind:

Jon lines are your friend. Try finning against a 2-3 knot current for 40 minutes. You'll see what I mean. You'll exhaust your gas supply before completing deco & as battles pointed out, not a good idea @ a 1.6 PO2

Scootering is all well and good. What happens when your scooter decides to crap out? Strong current + lengthy obligation w/ dead scooter = ??? You get the drift..

A few comments form someone who has been doing this stuff for almost 30 years now.

Fining against a 2-3 knot current? A knot is 2,025 yards in an hour. Try fining at 1 knot for 20 minutes and then talk to me, no diver can fin at 2 to 3 knots for more then a few seconds. Fully rigged you might be able to keep up with a 1/4 knot current if you are in good shape; others have talked about the effect on gas consumption.

Significant swells/chop can develop with the change of the tide, especially if the wind, ground swell, and tide get the right mix, you have to be ready for it on the open water.

You can let the line slip through your hand, have done it many times, it will not work in a current.

Live boating and drift DECO is fine, if you have a live boat. The drift deco vs. tied in discussion will not be settled here. You go with how the boat is run or you do not do the dive.

If you use a spool like a John line, you are using a John Line, live with it.

Scootering is great, how many have scooters? Everyone on the dive/boat? A scooter is a great tool, 95%+ don't have one.

A John line is just a readily available tool, use it when you need that tool.

I carry two lines that can be used as John Lines, one is what most would call a John Line, the other is wrapped around my lift bag as a rigging line. Put the two together and I can be 12-15 feet off the anchor line ridding sweet and stable while you are finding out how good your shoulders are and the effect of holding a 20+ minute death grip has on your hands.

 

[DA Aquamaster]

Drift deco also works fine in, for example, Florida, where the viz is generally good, predictable and the seas lay down a bit better a higher percentage of the time. But it is much riskier in the north atlantic where a combination of currents, high sea state, shipping lanes and sudden onset of fog and poor viz could prevent you from being seen or tracked by the boat on a drifting deco.

It is even worse if you are just one diver on an unplanned drifting deco while the rest remain on the line with the boat anchored. In the event you are not able to swim or scooter back to the anchor line, a very non DIR jersey upline will be very nice for you to have as it will keep you on the wreck. The boat captain always has the numbers so even if he has to pull the hook, the hook comes loose etc, he always knows where to find you if you are tied into the wreck with an upline.

Scootering the deco is in my opinion a poor choice. If the scooter fails you are pretty well screwed as I have yet to meet anyone who can maintain more than maybe 1 to 1.25 kts on a constant basis for say 30-60 minutes of deco. And your gas consumption will be on the high side so you had better have a great big reserve of deco gas along with you.

One thing I have also seen in north atlantic wreck diving is strong tidal currents. For exmaple you may tie into and dive a wreck during slack tide when currents are under 1 kt, but a long deco may leave you in a 2-3 kt current before you are done and most scooters will be hard pressed to hold a diver in position in a 3 kt current with stage and deco bottles attached.

All things considered it is far easier to hang on a jon line as it handles both the swells and the current in a very low tech failure proof manner.

While it may have originated in the caves I can assure you that there are hundreds of people diving DIR in open ocean enivronments.

For the OP, if there is a heavy swell running do your final stop deeper and don't try and hold on to anything like the anchor line. If you're not trying to stay attached to anything then you will move up and down with the water. If there is a current running then you will have to consider it's speed and look to either floating deco, kick against the current or use scooters to maintain position. As a last resort we have gone to using our spool as a sort of Jon Line but we let out enough line that we aren't affected so much by the ups and downs of the anchor line.

Thanks for making my point as to exactly why I do not look to DIR for the last word in what works in offshore north atlantic wreck diving. Parts of it make sense, but you alwayswant to adapt it to what will be optimum for the specific conditions and a Jon line is a cheap, low tech, easy to deploy solution to most current and swell related deco isues - far better, far safer and far more reliable than drifting, kicking or scootering in many situatons. Don't get me wrong, I like the DIR configuration as a whole, but I have been around long enough to realize the wisdom that can be gained from listening to boat captains and local non DIR divers who often have valuable advice about what works and what does not in specific circumstances even though it is often non GUE approved or promoted.

 

[John_B]

When I consider that "DIR" originated in a cave environment, the DIR forum does not tend to be my first resort for the last word on offshore diving subjects such as Jon Lines, SMB's, uplines, etc. You may want to consider posting in the general techncial forum.

You don't think AG knows a thing or two about tech diving?

 

[nadwidny]

Sorry, I'm not DIR and I'm not trying to start an argument but I've seen this in practice before and it shocked me. Doing deco, comfortably resting at 20ft on O2 (current and swell) watching two guys kick feverishly into the current because they refused to deploy a jon line or hang on the line. Maybe it's me, but working hard at 1.6 PO2 is not high on my list of things to do. On an anchored wreck dive, is this really the recommended approach?

We don't work hard or kick feverishly on deco. Even in heavy current. I guess that's the difference between those who know what they are doing and those that don't.

 

[nadwidny]

For starters, I'm not DIR.

Then go away. Nobody here cares what you think you know.

 

[nadwidny]

Thanks for making my point as to exactly why I do not look to DIR for the last word in what works in offshore north atlantic wreck diving. Parts of it make sense, but you alwayswant to adapt it to what will be optimum for the specific conditions and a Jon line is a cheap, low tech, easy to deploy solution to most current and swell related deco isues - far better, far safer and far more reliable than drifting, kicking or scootering in many situatons. Don't get me wrong, I like the DIR configuration as a whole, but I have been around long enough to realize the wisdom that can be gained from listening to boat captains and local non DIR divers who often have valuable advice about what works and what does not in specific circumstances even though it is often non GUE approved or promoted.

Yes, well, we have listened to the local non DIR divers in the very north Atlantic (Nova Scotia) who told us that our DIR methods would not work on their wrecks. We heard the non-DIRs tell us on the West Coast of Canada that our DIR methods wouldn't work in the current swept waters there. We heard from the non DIR divers that our methods wouldn't work in sub-zero temperatures under the ice. We consistently hear from non DIR divers that no matter what we are doing, DIR won't work. Guess what? They are wrong. For the non-DIR types to constantly tell us that what we are doing won't work since DIR is cave-based is ludicrous since we continually prove them wrong again, and again, and again in different environments all over the globe.

I've laid out the adaptations we use for different situations and in different environments and yet people continue to tell us that what we do won't work. Bizarre.

 

[vshearer]

I am posting this from the Decostop. It is only my take on this that one should be very wary of stops in rough conditions. If I offend anyone by this I apologize. I really admire Denton. Granted this is a deco dive, but I think it applies even to a NDL in certain conditions.

As reported by David Swift.


In the interest of full disclosure, and to complete my promise to Denton, I am posting the details of the dive and incident with the hope that it may help someone in the future. I welcome any constructive comments or discussions. While no dive is perfect, this one was about as good at it gets until encountering the surface conditions at the 20’ deco stop.

Please note – I am leaving this morning to attend to a family matter in New England so I won’t be able to respond for several days. However, I wanted to post this before leaving on my trip.

Details
- Denton was using 26/33 trimix, 50% and 100% deco. I had 23/33 and the same deco plan. (We normally dive GUE standard gasses but Denton wanted to try “best mix” gasses on a few easy dives). Denton mixed both of our back gasses (I was present while mixing mine) and we analyzed our own mixes twice (night before and morning of the dive).
- We finalized our dive plan en route to the wreck site and decided to quickly descend, scooter once around the whole wreck to get oriented, then explore the bow, debris field, boilers and engine in detail.
- The ride out was a little bumpy, but not bad; Denton slept about 1.5 hours during the trip out, drank water and did some stretching exercises about 10 min before we dropped the hook.
- We had a very pleasant dive, max depth 135’ (using scooters during the whole bottom time). We executed our dive according to plan, with the addition of circling the wreck a second time (but this time over the top deck) during mid-dive and then returning to exploring the bow/mid-ship area for the remainder of the dive.
- We maintained a horizontal position during the entire dive, including during deco.
- Several minutes before the end of our planned 45 min bottom time we stopped at the anchor line, stowed our scooters and lights, and began our ascent about 5 minutes earlier than planned.
- Our deco plan:
70’ for 1 min after switch to 50%
50’ for 2 min on 50%
40’ for 4 min on 50%
30’ for 5 min on 50% (we switched to back gas for an “air break” when done)
20’ for 20 min after switch to 100%
- Ascent went according to plan and was uneventful until the 30’ stop; the anchor line was angled between 35 - 45 degrees during the entire ascent but we felt no current between 120' to 30'. We ascended in a free floating face-to-face formation (not holding the anchor line)
- At 30’ we started to feel a strong surface current and changed formation to a stacked position. I was above and to the left and Denton was 3’ below me and to the right as we held the anchor line.
- At 20’ we took turns switching to 100% deco gas. Initially we didn’t realize how much the anchor line was jumping and we were pulled up to about 14’ during our gas switch; we returned to 20’ immediately after the switch (it took about 2 min total for both of us to switch)
- Per the plan, we maintained our 20’ stop for 20 min while on O2. The 20’ stop was extremely rough due to a strong horizontal current (approx 3 knots) and the anchor line was constantly stretching and jumping up and down 5’-6’. We were able to absorb much of the motion with our extended arms but were still being jerked up and down during the entire 20 minutes.
- I considered using a jon line but decided to avoid the additional task loading since we were focusing on maintaining our 20' depth and not loosing hold of the anchor line. Also, deploying a jon line would have required me to hook the anchor line with my elbow which would have reduced the length of arm-buffer and resulted in even more pronounced vertical movement. Denton also opted to not use a jon line.
- About 5 minutes into the 20’ deco Denton looked back at the hang bar which was diagonally behind us and shrugged. I looked back and shrugged back at him. We were both agreeing that it wasn’t worth taking a chance swimming cross-current for the hang bar in the heavy current. Normally there is a line between the anchor line and the hang bar but, due to the strong current and steep angle of the anchor line, the line connecting them was up near the surface and we would have to violate deco to use the line.
- Denton finished his deco stop first (he had started his timer about a minute before I did) and performed a controlled ascent past me (on my right).
- As he passed I gave him an “OK?” sign and he responded with an “OK”
- I switched hands (right to left hand) and raised my right shoulder so that I could watch him ascend.
- He stopped 3’ above me, still holding the anchor line, tested his neck reg and started a switch to back gas (we usually exited on back gas so that we can hand up deco bottles, particularly in rough water).
- Less than a second after he switched the reg fell out of his mouth (before he even cleared the reg or inhaled) and he let go of the anchor line and immediately was swept back by the current and started to descend and assume a head-down position. He did not display any sign of trouble or distress at any time; he just went from conscious to unconscious instantly. He never convulsed or displayed any movement.
- I immediately grabbed for him with my right hand while holding the anchor line with my left and was fortunate that I could catch him before he dropped away.
- I quickly hooked the anchor line with my left elbow and tried to replace his reg with my left hand but I could see that he was not conscious.
- I then hit his inflator button and kicked hard for the surface. The printout from my computer (attached) shows that about 10 seconds elapsed from the time of the incident, until the start of the emergency ascent; then shows that we went from 16’ to the surface in less than 10 seconds (my computer is set to sample every 10 seconds).
- The surface conditions had kicked up while we were on the bottom and were very rough. I estimate that we had 5’-6’ seas (it was only 3’ – 4’ when we went in).
- Once on the surface, I had to take my reg out to call for help and wasn't able to replace it because I was holding on to Denton and trying to turn him face-up with my right hand while holding on to the anchor line with the left so that we wouldn't be swept away.
- I was only able to get his face out of the water about 3 times but each time a wave slammed us back down.
- I quickly realized that I couldn't be heard under the bow so I kicked to the side of the dive boat and shouted for help again.
- The boat crew and other divers reacted quickly and threw me a line while I still had hold of Denton.
- A diver onboard jumped in with his street clothes and got Denton from me. I estimate that less than 1 minute elapsed from Denton loosing consciousness until I handed him off to the other diver.
- At that point I had ingesting a lot of water, was becoming exhausted and loosing hold on the line. Another diver threw me a tethered life ring and I was able to wrap my left arm around the rope a few times and bend my elbow to maintain hold.
- He then dragged me around to the back and others helped to get me back aboard.
- Once on board I vomited about a liter of seawater and regained my strength.
- With great difficulty the crew and other divers got Denton out of the water. The rescuers estimated Denton spent about 10 minutes unconscious before they could cut him from his equipment, get him on board and start CPR.
- They performed CPR on him for almost 60 minutes before he started breathing on his own and regained a heartbeat.
- We were both evacuated by USCG helicopter to Norfolk Hospital (I did not need admission).
- An initial MRI’s showed that Denton had an aneurism and a small embolism in his brain; and EEGs showed very little brain activity.
- The hyperbaric / dive doc had me give him a detailed briefing of our dive plan, gasses used, deco plan/execution, my observations when the incident occured, and actions taken by me and the surface rescuers. He later discussed the dive details with other diving specialists, including a 24-year Navy master diver, and said that their conclusion was that the dive plan was a good one and that they did not see any problems or have any concerns.
- Denton was put in a hyperbaric chamber for 7 hours Sat night – Sunday morning.
- A second MRI still showed the aneurism, but the embolism was gone.
- On Sunday afternoon the attending doctor took the family aside and told them that he felt very strongly that the aneurism caused the sudden loss of consciousness and that a small embolism was created when Denton stopped breathing and I brought him to the surface in an emergency ascent from 16’. He assured us that everything that could have been done was done once the problem occurred.
- On Tuesday morning, we were taken aback when another doctor told the family that he wasn’t sure if the aneurism was large enough to cause a black-out, and said that the aneurism might have just been a coincidence and that an embolism may have caused Denton to loose consciousness. However, he also told them that he wasn’t really sure and that “we may never know for sure”.
- Denton died quietly on his own on Wednesday, 14 Jun, at 0615.
- No autopsy was mandated or performed. I have not seen the death certificate and do not yet know the official listed cause of death.

Attachments:
- Deco planner screenshot showing Denton’s dive plan
- Screen shot of my Suunto Viper dive profile – this was independently compared to Denton’s VR3 and Vyper downloads and they match identically (I do not have a copy of a screen shot of his computer data but have seen hard copies)
- Screen shot of the 10-second-interval data sampling of the last 2 minutes of my dive computer. Again, this matches Denton’s data except his computer shows his controlled ascent past me at the completion of his deco time.

Lessons learned:
- Of course, I have given this dive lots of thought over the last week I can’t say that we should have done anything significantly different. The sea conditions were reasonable when we entered the water, the dive was pleasant and uneventful until the end, and Denton and I conducted our dive just as we have practiced and executed numerous times.
- One lesson learned, however, is something that I think incidently went right. As we all know, the first and last 5 minutes of each dive causes the buddy team to be split up since, during most dives, both buddies don’t enter and leave the water at the same time. After being tossed up and down on the anchor line for 20 min I was finishing my deco thinking about how rough it was going to be getting up the ladder. That prompted me to turn and watch Denton’s ascent and exit. Unfortunately, I can’t say that we always watched each other that closely at the very end of every dive. In this case, if I hadn’t happened to be watching him, we probably wouldn’t have known we lost him until I got on board. The take-away for me is that divers need to find ways to keep the buddy team together and watching each other on every dive until you are both on the surface and under the watch of the crew.

Just before Denton passed, my wife asked me how our dive was other than the problems at the end and I started giving her a technical description of gas mixes, depths, etc. She stopped me and asked again…”but how was the dive…did you both enjoy it”. Surprised at the question, I responded “yes, it was a great dive, we had a lot of fun exploring the wreck.” She then wisely stated “Good, it’s important that he enjoyed his last dive”. And, of course, she was right.

I hope that this information will be of assistance to others.

 

[D_B]

Thank you vshearer .. it was rough to read that and imagine what you must have gone through.

Is this an indication of how important it is to be able to hold a constant depth for your deco stop? (and for my safety stops) ... how can you maintian depth in such rough conditions? (my questions, not a comment on what happened)

I would have thought a jon line would help, but I guess attatching it is the problem, your going to be jerked up/down even more while attaching it ..... would having hook in one hand and switching to the other to install it, be too risky of being swept away if missed hooking it?
Edit: obviously you both thought so .. you have to be there to understand the conditions

And folks, this is the DIR Forum yanno

 

[battles2a5]

We don't work hard or kick feverishly on deco. Even in heavy current. I guess that's the difference between those who know what they are doing and those that don't.

Well they were the ones claiming to be "DIR", that's why I asked the question. Thank you for the constructive response.

Then go away. Nobody here cares what you think you know.

As always Nadwidny, a true ambassador of the sport