Almost out of air after descending against a strong current

[KeithG]

The Situation
The descent was down an anchor line to a wreck. The current was strong, estimated about 1.5 knots near the surface. The anchor line was close to horizontal. It was hand over hand all the way down. It was a good distance and slow going. I was last in a group of 4 (two buddy pairs) plus our guide (a highly experienced instructor). It was our group's 5th dive together over 2 days. My wife was my buddy. I was relaxed and calm. No fighting the current, no finning, just gentle breathing. I was "flying" above the line, nearly horizontal, but slightly head down. It was fun with the exception of the layer of jellies that we descended through. That required some bobbing and weaving, but a few stings on the face were inevitable. We got to the end of the rope (depth about 18 meters), swam off of the line into the current for a short burst, then sheltered behind part of the wreck for a couple of seconds. We then did a quick hop over over the wall onto a protected space that was big enough for the whole group. I checked my pressure gauge and did a double take. It was down from 200 to 50 bar! WTF?!?

I signaled to my buddy and she was shocked. I made it clear we were going to ascend immediately. Our pre-dive plan was to return to the anchor line with at least 70 bar left, so we were on the same page. She darted forward and got the guide's attention. I was already turning back towards the rope. The guide quickly came over and checked my gauge for himself. I wasn't panicking, but my heart was THUMPING. We made our way to the anchor line. I started to move up in a deliberate fashion, and the the guide told me to stop. Ten seconds later, he had made sure the other team was in control, and he came up to me and offered his primary, and he took his integrated alternate. I was surprised that he wanted to do that, since I still was thinking I would just simply ascend. But it seemed prudent, so we began sharing air and away we went. Once I found a comfortable position it was a relaxed, controlled ascent up the anchor line. Mercifully, the jellyfish layer was mostly gone. Just below the surface I swapped to my primary, surfaced and inflated my BCD without issue. Got to the boat and had an interesting conversation with my wife and the guide.

I suspected that something was wrong with my gear, but everything looked just as it did during my pre-dive safety check. I checked my pressure when I did my first check, my buddy checked it, I double checked on the inflatable boat that took us to the anchor line off of the bow, and my guide had each of us check and report to him before we entered the water. So I'm sure I started with a full tank. The guide is convinced that my alternate went into free flow while I was pulling myself against the current. He's seen it before at this very site. There wouldn't have been anyone behind me to notice, and the current would have swept the bubbles away from me before I could have seen them. It could even have happened when I was distracted by the jellies.

Lessons Learned (so far)

• Check your gauges often, no matter what. I was focusing on the descent and was convinced everything was just dandy, so I didn't feel an urgency to do it. I also didn't want to fall behind the group. Regardless I should have made a point to check. It's good that I did check when I got off the line, though. It was on my mind, and I did it as soon as we were in a safe place. If I hadn't done that I might not be writing this [shuddering]. I'm considering getting getting air integration with my dive computer to give some redundancy and to make it easier to check more frequently.
• Currents pose special risks. I wasn't aware that an alternate could free flow from the pressure that the current puts on it. If I had been aware that it was a possibility, I would have checked on it frequently to make sure the purge valve wasn't facing straight forward. I would also have been more likely to notice a funny sound.
• When critically low on air you should begin sharing air immediately. Don't wait until you are out of air. Sharing air immediately gives you the ability to deal with a contingency that causes you to separate later for some reason.
• My buddy made the right choice to get the guide's attention. Otherwise we would have just ascended up the anchor line, and I would likely have run out of air, since I was running through it faster than I thought. (I was surprised to hear that I was already at 20 bar when I started sharing air with the guide). We have practiced sharing air before, but what if her back was turned or something was distracting her just as I ran out of air? I could easily have panicked, and we all know how that story ends [shuddering].
• If my wife hadn't been able to get the guide's attention right away, we should have ascended immediately instead of heading for the anchor line. Share air, grasp arms and go up slowly. No safety stop. Despite the current, deploy the SMB at the surface, not at depth, in order to avoid additional extra task loading while sharing air. I'm confident that the experienced and competent boat crew would have seen us at the surface with the SMB inflated, even after drifting.

I hope this helps others avoid this situation or deal with something similar in the future. I look forward to learning more from the comments.

BTW, we dove the same site again in a few hours. Great dive!

Definitely a situation to be aware of. One thing to think about is calling the dive sooner. Anytime I get into situations outside my very small comfort zone, I get fixated on my computer & gauges.

And I am happy to be the first one to call a dive. There is always the next dive...

I have twice been in a "too much current for poor old fat me" situation.

The first time my buddy & I finally reached the mooring line at the front of the boat after kicking may ass off and using the darby line to get there and immediately called the dive since we where both down to around 1500 PSI already.

Who knew the top half of the tank was that small?

The second time I called the dive about 15 minutes in since I was not happy with the current. My buddy was iffy but readily agreed. We did the night dive on the same site with no current. All were happy.

 

[Zippsy]

A final note on the captain: remember he dropped the guys who set the hook just fine. He certainly knows how to do it.

I think Dan is saying that the captain was negligent because he could only do that with two divers. That's easy to do. Try doing it with 18 divers at a time. It's obviously above this captain's ability. Also, the dive crew must have also been negligent because they thought a controlled drift up the line was easier than a blue (green) water ascent.

 

[boulderjohn]

I agree the Captain and Crew need to know what they are doing...how to run a dive boat and do drift drops. As to the divers....at the risk of sounding like a broken record, certainly more than 70% of the tourist divers that VISIT Palm Beach have not done drift drops before Palm Beach, and many are only OW certified divers....the thing is, this really is the EASY way for the divers....

It is harder on the Captain and crew...it is MUCH EASIER on the Divers.

Which is why I say, if the Captain can't do the job, don't use him.

And you know the captain can't do the job because....?

The first time I did a drop like that in that area was on a wreck called the Hydro Atlantic--I'm sure you know it. I was on a boat that did almost nothing but technical dives, so the captain was quite used to the process. We dropped two at a time. My buddy and I were the first to drop, and we dropped the precise second that the captain told us to go. We learned later that the second pair (there were only 4 of us) got into position and then dropped before the captain told them to, when the boat was still positioned directly over the wreck. We learned that from the captain, who told us that when we got on the boat, as an explanation for why we must not have seen them on the wreck. He was very surprised to learn that WE were the ones who missed the wreck. After 5 minutes of wandering around on the sand, we had blundered into it. It turns out there was no current that day, contrary to the captain's calculations. With his best skill--and remember that he does this all the time--he had dropped us in the wrong place. The people who dropped at what he thought was the wrong place landed squarely on the wreck.

On another occasion, we were planning to drop to a wreck called the RBJ. Everyone on the trip was an experienced tech diver. The captain announced that in his experience, more than half of the divers who attempt to reach that wreck on such a drop miss it. Since it is a very expensive dive, he suggested we try to let the DM hit it first. He did, and we descended on a line in a ripping current. A free drop would have been more pleasant, but it was sure nice to know we were certain to find that wreck at the end of the line.

I realize both wrecks are deeper and more of a challenge than the ones you are describing here, but in both cases everyone involved was much, much more experienced than you find in the divers of a typical recreational wreck dive. I think most recreational divers would gladly trade a 100% certainty of hitting the wreck for the joy of not having to use a descent line in heavy current.

I agree with Dan... we smart-bomb wrecks in 25-35 metres of crappy vis often... beats the crap out of trying to pull down a bloody line against 1-2 knots of current... actually, ANY current at all. Smart-bomb in and drift out.

A drifting ascent is a certainly a much more pleasant option than ascending the line in heavy current. In the dive to the RBJ described above, we descended the line (very difficult because of the current) to the wreck, but once we were done with the dive, we disconnected the line and ascended next to it, drifting along in the current. For those who have never done it, it feels like there is no current at all when you do this, because everything is moving at the same speed.

However, if you have no drifting ascent line, which is normally the case, then you have to ascend in buddy teams, providing your own line. You have to inflate a bag and send it up for the boat to follow, with a line from a spool or reel attached. Without that bag to follow, the boat has no idea where the divers are as they ascend, and there is a good chance the divers will not be seen when they surface. It is also much harder to do a proper ascent without the visual reference of the line. Does the average recreational diver have this kind of skill? (Last year we had an Accident & Incident thread about an experienced technical diver who sent up a bag from depth, was accidentally tangled in the line, got pulled to the surface, and died.)

 

[danvolker]

And you know the captain can't do the job because....?

The first time I did a drop like that in that area was on a wreck called the Hydro Atlantic--I'm sure you know it. I was on a boat that did almost nothing but technical dives, so the captain was quite used to the process. We dropped two at a time. My buddy and I were the first to drop, and we dropped the precise second that the captain told us to go. We learned later that the second pair (there were only 4 of us) got into position and then dropped before the captain told them to, when the boat was still positioned directly over the wreck. We learned that from the captain, who told us that when we got on the boat, as an explanation for why we must not have seen them on the wreck. He was very surprised to learn that WE were the ones who missed the wreck. After 5 minutes of wandering around on the sand, we had blundered into it. It turns out there was no current that day, contrary to the captain's calculations. With his best skill--and remember that he does this all the time--he had dropped us in the wrong place. The people who dropped at what he thought was the wrong place landed squarely on the wreck.

On another occasion, we were planning to drop to a wreck called the RBJ. Everyone on the trip was an experienced tech diver. The captain announced that in his experience, more than half of the divers who attempt to reach that wreck on such a drop miss it. Since it is a very expensive dive, he suggested we try to let the DM hit it first. He did, and we descended on a line in a ripping current. A free drop would have been more pleasant, but it was sure nice to know we were certain to find that wreck at the end of the line.

I realize both wrecks are deeper and more of a challenge than the ones you are describing here, but in both cases everyone involved was much, much more experienced than you find in the divers of a typical recreational wreck dive. I think most recreational divers would gladly trade a 100% certainty of hitting the wreck for the joy of not having to use a descent line in heavy current.

John, When George and Bill and I did our tech dives off of South Florida, we were VERY Picky about what boat, and what Captain we would use....A precise drifting tech drop on the Hydroatlantic is beyond the skill sets for most captains....it was easy for Lynn Simmons of Splashdown--If I wanted to land on a wheel house even 225 feet down like the Skycliffe, Lynne was famous for her ability to do this with ease....The RB is harder than the Hydro to drift to--limiting the captain pool alot...but that is Lauderdale--with much smaller currents than on Palm Beach tech wrecks--smaller currents mean less certainty that the ocean will take us to the wreck as we drift effortlessly at 220 waiting to see it.. ..This wreck we would dive with an anchor line, because it rarely had enough current to be significant..Plenty of times we just dropped on it though. If you can hit 200 feet deep in the first minute after leaving the platform, it is hard to miss a good drop. With a bad drop--you need a new captain

I don't believe in hundreds of tech drops any of our captains ever missed getting us on the wreck we were aiming for. But again, many captains will say they can do it...only a few can really pull off the tech drift drops to small targets.

For 90 feet and shallower, pretty much any Palm Beach Captain has the skill set to make this easy for 75% of the divers. There will be 25% that probably should not have a c-card, so they don't count
Slow descenders should either experiment with Mucinex D or more powerful sinus meds--Or...they should forget about wreck diving.

 

[Zippsy]

...but that is Lauderdale--with much smaller currents than on Palm Beach tech wrecks--smaller currents mean less certainty that the ocean will take us to the wreck as we drift effortlessly at 220 waiting to see it...

This raises a few questions but maybe I am taking your comments out of context. Please forgive me (and correct me) if I am. If a captain can drop you onto a wreck so perfectly in strong current, why can they do it in weaker currents? Also, I may have misunderstood you before but I thought they were dropping you onto the wreck with some sort of precision, rather than just getting you up current, telling you to swim to the bottom and wait for the wreck to come into sight. That doesn't take much skill at all, does it? All you need to do is figure out which way the current is moving. A bread crumb thrown overboard could do that, no?

 

[gcarter]

Slow descenders should either experiment with Mucinex D or more powerful sinus meds--Or...they should forget about wreck diving.

With all due respect, I find that offensive and elitist. I can be slow to clear and it has nothing to do with sinus congestion or inflammation. Nor am I interested in ingesting unnecessary medications in order to meet someone else's view of how I should dive. You prefer a free descent, fill your boots. I'll dive my line and enjoy my wreck dive all the same.

 

[dumpsterDiver]

And you know the captain can't do the job because....?

The first time I did a drop like that in that area was on a wreck called the Hydro Atlantic--I'm sure you know it. I was on a boat that did almost nothing but technical dives, so the captain was quite used to the process. We dropped two at a time. My buddy and I were the first to drop, and we dropped the precise second that the captain told us to go. We learned later that the second pair (there were only 4 of us) got into position and then dropped before the captain told them to, when the boat was still positioned directly over the wreck. We learned that from the captain, who told us that when we got on the boat, as an explanation for why we must not have seen them on the wreck. He was very surprised to learn that WE were the ones who missed the wreck. After 5 minutes of wandering around on the sand, we had blundered into it. It turns out there was no current that day, contrary to the captain's calculations. With his best skill--and remember that he does this all the time--he had dropped us in the wrong place. The people who dropped at what he thought was the wrong place landed squarely on the wreck.)

The captain should have told you, or you should have asked... what his assumption was for the direction of the current as he was setting you up for the drop. You NEED to know this.

IF you had gotten this critical piece of information (and most likely he was assuming a current traveling north) so he dropped you south of the wreck 200-700 feet. If you know this information and you shoot down to depth and see that the bottom isn't moving then you know to swim north. If you see the current going the opposite direction, you can (should) abort the dive and ask for a "do-over" . But all divers need to know what drift the capt is setting them up for so they avoid "wandering around on the sand"

 

[shoredivr]

C'mon up to the St Lawrence near Brockville. The wrecks are nearly all buoyed, and the style here is for most captains to tie stern-up to the mooring and divers jump into the variable 1.5 to 2.5 knot currents. One charter operator - thousand Island Pleasure Divers - will let an experienced group live drift into some wrecks, and honestly it is easier on the diver. However you need to keep out of the shipping channels and know how to use an SMB. Do not come up in the shipping channel with your SMB, they can't stop those freighters on a dime and you and the operator will get a hefty fine if they need to close down the St Lawrence Seaway.

Nimoh,
The thing is, I have seen the outcome so many times...of captains anchoring on a wreck in a high current, and where so many divers blow a huge amount of air on the way down....creating massive CO2 and fatigue, and potentially getting to the point of exhaustion that we might expect could cause tunnel vision and poor choices--even dangerous or catastrophic ones. The average diver was never trained to work at the edge or aerobic failure and to go anaerobic in their efforts underwater. The mental and skills portion of their performance is severely impacted by this. Even if they don't end up doing anything stupid in this state, their potential for DCS increases massively with the greater likelihood of muscles being severely constricted by over-exertion--and of poor off-gassing on ascent.

In practical terms, After you have seen this scenario a few dozen times, you pretty much know the Cluster F%$k that will ensue from a high current anchor dive. A captain knowing this, doing it anyway, is putting the money taken in from the divers-paid to take them to this wreck----over the importance of obvious safety. If he had the SKILL LEVEL required, he would do this in a series of drops --based on descent speeds, and he would be PREPARED with SMB;s or other means to track the divers --Or...he would abort this location. Good captains that care, don't do this high current anchoring. Poorly skilled captains do. Ones that don't know any better do.

I have done drifts in bad vis--less than 10 foot vis, to 100 and even 280 foot deep wrecks. The vis is a problem only on a bad drop ( bad technique from the captain) or with tiny wrecks....or for divers that are incapable of fast descents due to sinus issues. Of course, for this there is Mucinex D

Palm Beach is a place where you can see how easy drift drops are....and where the Captains do this so effortlessly you really have to wonder why this is not done all the time..by captains everywhere.

 

[Doppler]

C'mon up to the St Lawrence near Brockville. The wrecks are nearly all buoyed, and the style here is for most captains to tie stern-up to the mooring and divers jump into the variable 1.5 to 2.5 knot currents.

I have dived the St. Lawrence a few times and can't say I've experienced currents between 1.5 and 2.5 knots. One knot will move an object at about 30 metres a minute... 2.5 knots translates to 75 metres a minute. I recall one day drifting from the bow of the Jodrey to the stern (a distance of about 200 metres) and it took a little less than seven minutes.

As you say, the current is variable, but surely slack is less than 1/2 knot and full-on gates down-river wide open it's 1.5 knots.

Now the Eastcliffe Hall has current that can top out at more than two, but it's a way downstream where the river is much narrower with no islands to interfere with flow.

 

[meagicano]

I have dived the St. Lawrence a few times and can't say I've experienced currents between 1.5 and 2.5 knots. One knot will move an object at about 30 metres a minute... 2.5 knots translates to 75 metres a minute. I recall one day drifting from the bow of the Jodrey to the stern (a distance of about 200 metres) and it took a little less than seven minutes.

As you say, the current is variable, but surely slack is less than 1/2 knot and full-on gates down-river wide open it's 1.5 knots.

Now the Eastcliffe Hall has current that can top out at more than two, but it's a way downstream where the river is much narrower with no islands to interfere with flow.

Variable is a good way to put it. Dive site conditions regularly change. We were doing the Lillie (to be followed by a drift) which I have done a few times, usually with a slight surface current. One night this summer the current was significantly stronger than I remember ever experiencing on the site - we were completely horizontal pulling ourselves along the line on the surface and all had to catch our breath a bit before descending and upon hitting the bottom.

I am a terrible judge of current speeds (I can say it definitely would have been over 1, based on the 30m/minute calculation) but those of us who dive regularly up here know that you can't be too complacent.

When I did the descent on the Lillie (to get back on topic) I didn't check my SPG until the bottom because I was focusing on going down the line. I tend not to check my SPG on descent because I dive with HP119s - this appears to be a bad habit I should change.