Downcurrents

[vladimir]

I encountered one in the Philippines recently, and have encountered them on several occasions in Indonesia. Anticipating them is half the battle, in my opinion. Things to watch out for: the fish are pointing straight up and finning without moving; eddies or large areas of strangely flat water on the surface; substantial horizontal currents, especially if two currents meet; drop offs; the dive site is called Washing Machine or Peleliu Express or something like that. A good dive briefing should alert you to the possibility of vertical currents.

An increased gas reserve will give you more leeway to keep a challenging dive from becoming a tragedy. Ever since I heard a story (I don't know how reliable it was) of divers being sucked to depth from the surface in Bali, I am more scrupulous about inflating my bc upon surfacing.

 

[gypsyjim]

These discussions since the first post on the accident this last weekend off Cozumel have certainly got me thinking.

One consideration that I had never thought of prior to this discussion, was Oxygen %,, and how easy it might be for such a current to pull a diver well below their maximum depth for the Nitrox % they are breathing, before they had any chance to get away from that current, or otherwise prevent the nearly instant descent.

Sure makes one rethink the basics one thinks they know.

 

[Rich Keller]

I have been certified since 2008 and am now a PADI instructor. During this time I have managed to avoid/not learn about/not be exposed to a new thing I am learning about in the past couple of days called a downcurrent. So while this question is inspired by a real life event, I am really just looking to educate myself.

What does everyone have to say about downcurrents? What are they? Why are they? Where are they? How do you avoid them? How do you survive them?

Please advise...thanx...

You deal with this the same way you deal with a rip current at the beach. You swim at a 90 degree angle to the current and away from the wall until you are out of it. I would also not inflate your BCD while in the current as you will present a greater surface area for the current to push against and may end up in an out of control assent once you are free of the current.

 

[danvolker]

Another reason to use good freediving fins, rather than something almost useless in a big current like split fins.....with a quick blast away from the wall, the freedve fin wearing diver could be out of the down current, making it only a mild inconveniance.

 

[MXGratefulDiver]

I think I'd rather head to the wall than away from it. For one thing the current is bound do be slower near the wall due to friction, and you can grab on to the wall and climb up.

Adam

Not necessarily. a few months back I got caught in a downcurrent on a clay wall. Grab onto that and it just comes off in your hand. The bottom sloped down to another wall that started at about 100 feet and went down to about twice that. I seriously wasn't prepared for those depths ... and about the only thing we could do is work our way to the top of the wall and over it to a place where there was something to hold onto. We did this by inflating our wings and kicking like hell. By the time we got to where there was something to grab ahold of, both of us were near exhaustion, and all we could do is grab ahold of some giant barnacles and hang on till the current died down a bit. Most downwellings are transient, which means if you have the option of just grabbing ahold of something and waiting for a few minutes, it'll pass.

Downwellings can be anything from mildly annoying to life-threatening ... depending on where they happen and how strong they are. We have an interesting one at one of my local dive site that creeps up from time to time ... I wrote an article about it once ... click this link, then select trip report called "Miso Soup" to read it ...

... Bob (Grateful Diver)