What to do with Down Current?
- Thread starter Evan Soon
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I was caught in a weak-medium down current in Maldives a few months ago. What I did was to swim out and up from the wall at about 45 deg, which worked pretty well. I also considered inflating my SMB but did not as I was too busy dealing with other issues.
Of course, things were a bit more complicated because my buddy and the DM were obliviously floating at 5m some distance away as they were not caught in it at all. Plus, another pair was below me, closer to the wall and I could see they were stuck in the downcurrent (more so than me) and being blown down.
That meant watching my depth and deciding how hard to fin upwards, watching the DM group above/forward of me, then spinning around to locate the other pair below/behind me and signalling urgently to them to swim up, multiple times, which was rather disorienting. I later found out the other pair could only see me and use me as a positioning guide - the DM group was too far away and we had moved into the deep blue. Luckily, I made it a point to stay within visual range of them.
Looking back, it was fortunate that a) the down current was not insanely strong, and b) I had read about down currents and watched videos on it. The pair below had not even heard of down currents and only realised afterwards how much danger there was.
Of course, things were a bit more complicated because my buddy and the DM were obliviously floating at 5m some distance away as they were not caught in it at all. Plus, another pair was below me, closer to the wall and I could see they were stuck in the downcurrent (more so than me) and being blown down.
That meant watching my depth and deciding how hard to fin upwards, watching the DM group above/forward of me, then spinning around to locate the other pair below/behind me and signalling urgently to them to swim up, multiple times, which was rather disorienting. I later found out the other pair could only see me and use me as a positioning guide - the DM group was too far away and we had moved into the deep blue. Luckily, I made it a point to stay within visual range of them.
Looking back, it was fortunate that a) the down current was not insanely strong, and b) I had read about down currents and watched videos on it. The pair below had not even heard of down currents and only realised afterwards how much danger there was.
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I was going to say that I'd line the bottom of my bird's cage with it,
but then, I re-read the title and saw that it was a different thing.
Never mind.
but then, I re-read the title and saw that it was a different thing.
Never mind.
I read that, in a group some are pushed down and some others aren't, how far were you from your dive buddy or dive guide when that happen?, I was thinking that this will be a large volume of water that covers a big area, how deep was the sea/ocean bottom ? I guess it has a big influence right
PeterNBiddle
Contributor
Eeeeeeeeeeeeeeeeeeeeeeek!!!! Honestly one of the worst things to do, and best way to get an uncontrolled ascent.
Best thing (unfortunately) is to hold on to whatever you can and wait it out. If it's lasting longer than you would hope, start climbing up. If none of that works, the blue option is still there.
I've had a friend who was a DM in Komodo and had to hang on to the reef with his tank banger with two of his guests grabbing onto him. Down current subsided, and they were able to continue the dive at that point.
My thoughts : Current out in the blue is unknown. Reef is known. Stick with what you know unless the solution you have isn't cutting it.
I've seen a lot of people mention swimming away from the wall to get away from the current. This is correct in my experience in surge, but with current, you're going to have more of a friction factor (the slower the current is) the closer you are to the reef. It's fluid dynamics.
Again, unless you're sure you know what the current is like out farther in the blue, best to stick to the reef and wait it out (extenuating circumstances excluded).
Source : Done lots of work in Nusa Penida and from experience with friends that work out by Komodo. Also a chemical engineer and know a bit about fluid dynamics.
marcushall
Registered
So, as an absolute novice who has never experienced down-current (or up-current!), the whole idea is a little bit freaking me out..
If one is dealing with this, and hopefully eventually escapes the current (either it subsides, or swimming across the current, or whatever).. If you find yourself very deep, obviously you want to get back up. If you descended very quickly, you haven't absorbed much nitrogen yet, so do you ascend relatively quickly for a bit, then slow down after a while, or do you do a slow ascent back to a normal depth, or what?
In the case of an up-current, if you find yourself suddenly taken from say 80 feet to 20 feet, do you go back down, stay there, or what? I'm sure that I read that if a diver surfaces suddenly, that the crew on the surface should not try to take the diver back down, that they cannot do decompression that way. So, if you find yourself in that position, can you effectively help things by going back down?
It sounds common enough that if you dive in various areas this is likely to happen to some extent sometime, so it would be great to know what the best recovery strategy is... Better still to be able to remember it and execute it when the need arises.
If one is dealing with this, and hopefully eventually escapes the current (either it subsides, or swimming across the current, or whatever).. If you find yourself very deep, obviously you want to get back up. If you descended very quickly, you haven't absorbed much nitrogen yet, so do you ascend relatively quickly for a bit, then slow down after a while, or do you do a slow ascent back to a normal depth, or what?
In the case of an up-current, if you find yourself suddenly taken from say 80 feet to 20 feet, do you go back down, stay there, or what? I'm sure that I read that if a diver surfaces suddenly, that the crew on the surface should not try to take the diver back down, that they cannot do decompression that way. So, if you find yourself in that position, can you effectively help things by going back down?
It sounds common enough that if you dive in various areas this is likely to happen to some extent sometime, so it would be great to know what the best recovery strategy is... Better still to be able to remember it and execute it when the need arises.
mikeycanuk
Contributor
Done lots of drifts but never the down current. Scary for sure, but the real danger (and what's freaking me out) would be on nitrox and getting pushed below MOD. Considering you'll be breathing faster than normal..yikes! And I have a diving trip to Komodo next year.
There is a washing machine on the Niagara river, I wonder if I could get someone to take us through it to get some idea of crazy currents.
There is a washing machine on the Niagara river, I wonder if I could get someone to take us through it to get some idea of crazy currents.
bakodiver391
Contributor
If you find yourself suddenly surfacing in an upwelling, I would do a self check for any injuries or symptoms of overexpansion, then if safe to do so, head down to around 30 feet and do a very slow ascent with 15 minute safety stop if possible. It's not cast in stone, but generally accepted that you have a couple of minutes grace to make up omitted deco or safety stop by heading back down. Commercial divers do it all the time when entering the chamber to do surface deco.
I recently experienced a severe down current while diving Open Circuit and taking photos with a large DSLR camera set up. It was at the end of an interesting drift dive basically along a wall quite close to shore at a Komodo island dive site. I had completed my safety stop and was about to ascend when I was caught in a down current which within what seemed a few seconds had taken me from 5 to 25 meters. I still kept going down to 35m despite fully inflating my wing. If wasn't so scary watching your exhaled bubbles descend faster than yourself is quite an unreal experience. Anyway I tried to swim out away from the island (wasn't close enough to grab hold of anything otherwise I would have) and eventually got out of the extreme down current. I still had to fin pretty hard to get back to the surface even with the wing fully inflated. When I did eventually surface I was more than 400m out from shore, so it was quite a wild ride! My buddy managed to grab hold of the reef and climb up hand over hand and just made it back with about 10 bar.
BTW I usually dive quite conservatively so had plenty of gas left at the end of this dive (100 bar) but I blew threw pretty much all of it by the time I was back on the surface (15 bar), so that conservatism certainly saved my butt.
Not sure I agree about the comments of trusting your DM. Our guy, unbeknown to us, had not dived the site before and when the current hit, he saved himself and left us behind. Needless to say neither my buddy or I were impressed by his actions.
Not sure I have any advice about how to prepare for this. SMB is a good idea, but in my case even though I had one I did not have a chance to deploy it. I can't really describe just how fast the current took me. Drifting with the SMB inflated for the whole dive is something I would consider in the future. I would also seriously consider diving in a tropical drysuit so I had redundant source of buoyancy (I am usually a cold water diver and always in a drysuit, so am comfortable with this). Diving conservatively and keep thinking are probably the two things that saved me.
Cheers
Larry
BTW I usually dive quite conservatively so had plenty of gas left at the end of this dive (100 bar) but I blew threw pretty much all of it by the time I was back on the surface (15 bar), so that conservatism certainly saved my butt.
Not sure I agree about the comments of trusting your DM. Our guy, unbeknown to us, had not dived the site before and when the current hit, he saved himself and left us behind. Needless to say neither my buddy or I were impressed by his actions.
Not sure I have any advice about how to prepare for this. SMB is a good idea, but in my case even though I had one I did not have a chance to deploy it. I can't really describe just how fast the current took me. Drifting with the SMB inflated for the whole dive is something I would consider in the future. I would also seriously consider diving in a tropical drysuit so I had redundant source of buoyancy (I am usually a cold water diver and always in a drysuit, so am comfortable with this). Diving conservatively and keep thinking are probably the two things that saved me.
Cheers
Larry
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