First-hand account of down current, with video footage

[Bison Ravi]

Even if the bottom is at 400 feet?

I'm sorry, english is not my first language, maybe I was not clear. What I meant is in some dives, you have to swim against the current. When you are close to the bottom, that is where you should go, because that is where the current is less strong, most divers know that.

I am trying to show with an exemple most divers know the way I think of wall dives and down current; a down current next to a wall is similar to a horizontal current. The current is less strong next to a surface (the wall).

 

[t-mac]

I'm sorry, english is not my first language, maybe I was not clear. What I meant is in some dives, you have to swim against the current. When you are close to the bottom, that is where you should go, because that is where the current is less strong, most divers know that.

I am trying to show with an exemple most divers know the way I think of wall dives and down current; a down current next to a wall is similar to a horizontal current. The current is less strong next to a surface (the wall).

I'm confused. Forgive me, but I haven't experienced this, but I thought I read here and elsewhere that you should move AWAY from the wall in a downcurrent. To me that makes sense since it is caused by the flow from shallower water over the wall into the deeper water. If you move away, it intuitively makes sense to me that the current would be weaker. Can someone please enlighten me.

 

[Bison Ravi]

The person that gave me this advice has been diving for 45years in cozumel.

The only time I experienced a very strong down current was in Komodo and after getting close to the wall and moving horizontally for about 20 meters, the current disappeared.

 

[Splitlip]

The person that gave me this advice has been diving for 45years in cozumel.

The only time I experienced a very strong down current was in Komodo and after getting close to the wall and moving horizontally for about 20 meters, the current disappeared.

Your analogy makes perfect sense to me as 99 % of my diving is in horizontal currents I'll admit I've never done a wall like this with vertical currents so I don't know all the dynamics, but I certainly know what you mean.

 

[MXGratefulDiver]

Please add my thanks to Scurby for posting the video. It is very hard to react to an emergency situation and for one I think the father reacted very well when taking into account the experience and the situation.

I won't repeat all that has been said, but would like to point out something that is bothering me a lot in many of the comments. Please excuse me if this has been said before, but I didn't see it.

Many people are saying "if caught in a down current, get away from the wall". I'd be interesting if someone could enlighten me because to me, that sounds like bad advice.

Here is the way I see it: When you are trying to swim against a current, you get to the bottom. Why?

1-Because of the friction created by the bottom, that's where the current is the less powerfull.

2-You got something to hold on into if the current is too strong to swim against. You can also crawl your way up the current.

I believe the same is true for a wall when in a down current: the current is less powerfull next to the wall, and you can hold on to it and either wait for the current to be less strong or follow the wall to get out of the current horizontally.

What if you go over the blue and the current isn't lower? You could get pretty deep very fast, with nothing to stop you.

Think of the downwelling as an underwater waterfall. Yes, you can cling to the wall ... assuming it's solid enough to support you ... but you're still underneath the waterfall. By swimming away from the structure, you swim out from underneath the falling water.

Sometimes clinging to the structure is not an option. The last time I experienced a downcurrent was on a clay wall. Grabbing the wall would only make it come off in my hands. Swimming away from the wall steadily reduced the downwelling until it was manageable enough for me to make a normal ascent.

... Bob (Grateful Diver)

 

[Bison Ravi]

Some prefer to get close to the wall and crawl up, but I don't as you are not out of it really. Still got to deal with it at the top. This thread mentions the DM rescuing two who did that and were stuck. Horizonal might work, yeah - as whether you go horizontal or away, the currents are generally narrow like rip currents on a beach.

Maybe the 2 at the top where just shaken up. If the DM did it two times in a row, it must have been possible.

My point is these currents never last long, and are pretty narrow. Personally, I prefer to have something to hold on and to stop me from getting deeper that to go over the blue and hope I get out of the down current before I'm too deep and out of air. But this is only my opinion, and I'm not trying to convince anyone. Do as you feel is best for you

 

[MXGratefulDiver]

Maybe the 2 at the top where just shaken up. If the DM did it two times in a row, it must have been possible.

My point is these currents never last long, and are pretty narrow. Personally, I prefer to have something to hold on and to stop me from getting deeper that to go over the blue and hope I get out of the down current before I'm too deep and out of air. But this is only my opinion, and I'm not trying to convince anyone. Do as you feel is best for you

The DM is probably experienced enough to know how to "read" the current ... analogous to what experienced cavers do when working against the flow in a cave. By choosing your route along the structure carefully, a knowledgeable diver can use the structure to "hide" from the worst of the current. This takes a certain amount of local knowledge ... usually derived from having experienced the current at this location before and knowing which route will provide the path of least resistance.

As you say, downwellings are transient, and usually don't last long. However, the combination of depth, exertion, stress and the AL80 scuba tanks they use in places like Cozumel can result in an OOA long before that transient current decides to let go of you.

... Bob (Grateful Diver)

 

[Bison Ravi]

Think of the current as an underwater waterfall. Yes, you can cling to the wall ... assuming it's solid enough to support you ... but you're still underneath the waterfall. By swimming away from the structure, you swim out from underneath the falling water.

Sometimes clinging to the structure is not an option. The last time I experienced a downcurrent was on a clay wall. Grabbing the wall would only make it come off in my hands. Swimming away from the wall steadily reduced the downwelling until it was manageable enough for me to make a normal ascent.

... Bob (Grateful Diver)

I'm sure there are many occasions when holding on to the wall is not possible. In some cases just hiding behind or below a coral formation is enough to get away from the current. Sometimes just being really close to the wall is enough to make it manageable to swim horizontally. And I'm sure sometimes the only option is to swim away over the blue.

Very strong down currents are not common at all in most places. Most divers will never encounter them. I just think it's good to know all possible options, so when it happens to you, you can use what you know to decide what is best for that situation.

 

[InTheDrink]

hmm... I'm trying to visualize what exactly the circumstances would be where you have a lot of current and would't want to descend as quickly and as close to each other as you could to avoid being separated?

Want and can are different things Mike. Surely a dive god like you would know this?

Mostly yes can drop near same time but I've had several where not possible. Boat needed to do full circle per diver to drop them so's they'll hit the line/reef/whatever. It's mainly cos there's not enough space to safely drop together. Interestingly on my last dive the owner and buddy tried to drop near same time and his budddy and rebreather dropped right onto owner who had gotten pushed back into boat/props in the current. Pure luck it didn't take him out.

John

---------- Post added April 25th, 2012 at 08:15 PM ----------

I'm sure there are many occasions when holding on to the wall is not possible. In some cases just hiding behind or below a coral formation is enough to get away from the current. Sometimes just being really close to the wall is enough to make it manageable to swim horizontally. And I'm sure sometimes the only option is to swim away over the blue.

Very strong down currents are not common at all in most places. Most divers will never encounter them. I just think it's good to know all possible options, so when it happens to you, you can use what you know to decide what is best for that situation.

It's not always a bad thing to fight a current (although generally it is) but in raging currents fighting it is a bad idea. That would include hanging on to walls, hooking in with reef hooks, or generally facing in the direction the current is coming from. Here's one link (Death in the Galapagos: Undercurrent 05/2010) there is another I can't find that was truly harrowing of a girl reef hooked in to a current so strong she couldn't release herself from the reef hook. And died.

Please don't get me wrong. I love currents, typically the stronger the better when there's the chance of big stuff around. But they have their challenges and working out how to deal with one will depend on various factors.

John

 

[vladimir]

It's not always a bad thing to fight a current (although generally it is) but in raging currents fighting it is a bad idea. That would include hanging on to walls, hooking in with reef hooks, or generally facing in the direction the current is coming from. Here's one link (Death in the Galapagos: Undercurrent 05/2010) there is another I can't find that was truly harrowing of a girl reef hooked in to a current so strong she couldn't release herself from the reef hook. And died.

Please don't get me wrong. I love currents, typically the stronger the better when there's the chance of big stuff around. But they have their challenges and working out how to deal with one will depend on various factors.

John

Here's the other thread you were looking for:

http://www.scubaboard.com/forums/basic-scuba-discussions/25725-lessons-learned-death-palau.html

Thanks for the link to the Undercurrent article. Unlike the thread, though, it doesn't clearly link the young woman's death to fighting a current. It is clear that the victim and the author were in over their heads, however. If you're relying on the divemasters to do your pre-dive check for you, then you are in way over your head. That is the lesson of this thread, the thread I just linked to, and the Undercurrent article.

Reef hooks are debatable. I have hooked in to reefs, and I have done cling-to-the-rocks-in-the-current dives, and I've done them safely, in my opinion.