Deadly Down Current

[Dadvocate]

I should go ahead and admit that I don’t have much more than anecdotal references to give with this particular incident because it didn’t happen to me. Instead it was an experience a good friend had that he shared last night over dinner. The story he told me scared me enough that I thought I would try to get better understanding of it by posting what I do know here and getting some calming and sage advice from the SB membership.

As his story goes, he was in Puerto Galero doing a drift dive somewhat early in the day to about 30 meters. He was with a highly experienced tech diver at the time so things were meant be easy.

As they reached depth something rather “horrifying and almost surreal” happened as he described it. A monstrous down current grabbed them and started dragging them downward off the reef. My friend said that he needed to fully inflate his borrowed OMS tech BCD. His buddy had to do the same as well. On top of this they still needed to kick consistently to maintain depth. He said that he had to stare at his dive computer which was beeping like hell while he kicked to get some sort of orientation. It showed him to be at 58 meters, nearly double what they had planned for! And there was a lot of empty space still below them.

As I sat at the table drinking wine and pondering this scary situation, he told me that he knew he was suffering terrible nitrogen narcosis and he was breathing heavily as well due to the stress. He swam to his more experienced buddy who could tell immediately that my friend was in distress. He tried to warn him not to breath too heavily. They locked an arm. His buddy then inflated his floatation sausage to get more lift and the two began working their way against this down current to get back to the surface.

You can probably guess what happened next. The current let go and the two of them had to purge air quickly at about 28 meters, which they did successfully.

Luckily, he told me, this happened so early in the dive that they both had plenty of air. The entire dive lasted something like 18 minutes.

Later at the bar, my friend’s buddy came to him to talk about the incident and to congratulate him on keeping calm “enough” so that they could make it back. He told him that if he had lost it down there, his buddy would have to have left my friend on the spot, a chilling thought that made me shake when I heard it. Then he added that it was a good thing that they had tech BCDs. If they had had recreational BCD’s, he claimed, they would have been goners.

I am pretty shaken by this, especially since Puerto Galero is in my near diving future. I’m off to dive there next weekend. My friend’s explanation concluded with the idea that these things do happen and, well, diving is dangerous.

I guess what I want to know is if this tale is something that I should take at face value (my friend is not one to exaggerate by the way). I am also very concerned about this notion that recreational BCD’s wouldn’t have had the lift to pull them out. Is this an exaggeration, or should I be thinking about another BCD?

Also, if this strong current is possible, what causes it?

Thanks for any feedback you can give me.

Cheers!

 

[dive_lover88]

wow that's scary!!

I had an experience too myself. Only difference was that it was an up current.

It happened last dec in Manado, was doing a wall dive. The current was quite strong at one point that we had to turn back. During the trip back, when i turned to check on my bud, suddenly i was flipped over onto my back and on a strong current upwards. I immediately deflated my Bc all the way and tried to flip back. I managed to get out of it when i reached the edge of the wall and pull myself over. Discovered that i was dragged upwards of 10m from 20m. Was a very scary ride!!

Thank God that nothing bad happened.

Yea i would also like to know how this happens.

Safe Diving
Darren

 

[Ed Palma]

My buddy also had a story like this one - just off anilao at Mainit point. Three of them went straight down more than a hundred feet in under a minute - this, in spite of furiously swimming upward and inflating their BCs. They also locked arms and subsequently managed to break free from the current and aborted the dive. Of course, he only told me this story when I was just a newbie diver, after he managed to convince me to do the Canyons in Puerto Galera.
Now that was one heck of a ride.
As for "tech" BCDs versus recreational BCDs, I think that stab jackets have a lot of inherent buoyancy in them. Even when fully deflated. I take it then that your friends were using wings, and that the additional lift came from wings meant for doubles. Were they using single tanks on the dive? My old stab jacket had a capacity of around 18L. Way more than I would ever need on a single tank. If they were indeed using wings for doubles with single tanks, then in this instance, the extra buoyancy might have helped them. Otherwise, I think that wings should be properly sized, to avoid streamlining issues with excess material. I guess I would've also done the same though and used my SMB for additional buoyancy. I've also toyed with the idea of dropping weights as a last resort, but I would like to hear the opinions of the gurus of the board regarding this.

 

[Dadvocate]

Yes, the Canyons in PG is one hell of a ride, I agree. But the sweet lips and Treveli inside are nice to gawk at when they are down there to welcome you. I’d hoped to try this out next weekend come to think of it. I’m not sure why this current thing is giving me the creeps. I’ve been in the Canyons five or six times in strong current, mind you sans a Poseidon-like death grip dragging me into the abyss.

“They also locked arms and subsequently managed to break free from the current and aborted the dive.’

30 meters in under a minute. That sounds about right compared to what my friend said last night. I’m glad to see that they got out of it. Mainit Point. That was my last dive when I was out in Anilao about six week back. How did they manage to get out, how much air did they use up, and what type of BCDs were they wearing if I may ask?

I’m curious what the protocol is in these cases, if a direct upward swim using energy and air is needed given the forces involved or perhaps getting neutral buoyancy ASAP is the right thing followed by swimming laterally away from (or along) the reef, kind of like swimmers in a rip tide? I hope that doesn’t sound stupid.

Up currents a swell. I guess that shouldn’t surprise me, really. I’ve experienced both types of currents in the Philippines to much lesser degrees while diving. Why wouldn’t it hold that these massive currents would behave the same way moving up and down?

Cheers!

 

[El Orans]

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A ScubaBoard Staff Message...

Moved to Near Misses and Lessons Learned.

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[Cave Diver]

I've heard similar stories of down wellings from buddies diving in Cozumel. Although not sure what causes it, it seems as if the current runs close to the wall. The best way to deal with it would be to swim away from the wall far enough to break free of the current then do a controlled ascent to shallower depth. Once you are clear of the top of the wall you shouldn't be in any further danger from it, as the current will be below you.

 

[tboxcar]

Quite interesting, and some what frightening. I have been to both Manado and PG many times, was just on the 'Canyons' back in September. Although the currents are strong there, I have never felt anything 'out of the ordinary' that is a massive down current or up current. Would be curious as to how this occurence takes place in the ocean???

 

[TSandM]

We experienced both up and down currents in Indonesia, although none as strong as what's described in the OP. They're scary, and a powerful reminder that the water is much stronger than any diver. I found that I could spot the places where the current was likely to go up or down, because the wall would change directions, and it was like the moving water would hit it and "splash". That may not always be the case, but it worked for me there.

The advice I have always seen is to do what you need to do with respect to buoyancy (eg. inflate and kick up in a down current) but mostly to try to get away from the wall, because these currents are generally fairly narrow and you can get out of them.

 

[ce4jesus]

Just like in air, these invisible updrafts and downdrafts are usually created by differences in temperature. They can be extremely powerful. I've never hit one in water but was in a plane when it fell a good 500ft before "catching" some lift. I've never given thought to running into one diving. I had an aquaintance tell me that he and a buddy ran into one and clutched the all, moved to oneside until they were out of it. Scary indeed. I think ditching your weights would give you plenty enough lift in a recreational BC.

 

[TSandM]

The problem with ditching your weights is that, once you do get out of the down current, you may very well not be able to control the subsequent ascent. It'd be better than drowning, but certainly wouldn't be my first reaction to being caught in a down current.