First-hand account of down current, with video footage

[Quero]

With the same logic I could say down currents don't always become weaker away from the wall soon enough to let you ascend normally.

That is correct, and it's precisely why I climbed the wall in the instance I described. But that course of action was based on a rational decision--I analyzed the specific set of conditions present at the time rather than following the mantra "stick close to the wall because the current is theoretically weaker there."

It is not a theory, it's a fact that the current is always less strong if you get closer to the wall.

That is also correct, at least in an absolute sense. In relative terms, though, the difference between being 1 meter from the wall and in actual contact with the wall may be the difference between speeding down a road in a car at 120 km/hour versus speeding at 110 km/hour when the maximum safest speed is 60 km/hour. It may not be safe enough close to the wall even if it's marginally safer than at 1 meter away from the wall. In this case, getting farther away from the wall may be a better alternative.

I'm talking about the currents in cozumel, not some tidal current in a channel.

Even in Cozumel. (Yes, the tides do greatly influence the currents there.)

 

[Bison Ravi]

I disagree.

When drift diving going left to right, the current is weaker due to the friction of the wall. This is the usual situation when we're doing drift dives: start at point A and finish at point B somewhere down the reef. A diver drifting 1m from the wall will travel at one speed and a diver 2m from the wall will usually drift faster. ​​​ I'm pretty sure the friction doesn't care if the water is going left to right or up to down.


(...)Otherwise it's 'usually' better to move out away from the wall to get back in to the main body of water and then ascend.

​​Or sometimes get close to the wall, move a bit sideways and enjoy the rest of the dive... Again mani different situations and many different things one could do

 

[supergaijin]

​​Or sometimes get close to the wall, move a bit sideways and enjoy the rest of the dive... Again mani different situations and many different things one could do

I agree- there are different things that one can do when exposed to current. A major difference in the 'normal' drift dive and one with a down-current is that there are 2 (or more) different currents interacting with each other.

If you're an eel you may have success getting underneath a downcurrent to go up against the wall. We ain't eels.

 

[MXGratefulDiver]

Different bodies of water react in different ways- temperature inversions, salinity levels etc. In some locations you can actually observe the changes in the water as shimmering or other disturbance. The cloudy water at the start of the OP's video indicates something like that. My point is that currents can and do behave in strange ways and as we have only a very limited 'big picture' of the divesite overall, it's very difficult to visualise ourselves in it as we are tiny and insignificant compared to the millions of liters of water that are surrounding us on any given dive.

... and sometimes how quickly you're descending can be deceptive, because you're in a moving frame of reference. I had to swim down and arrest the descent of someone dear to me a couple months ago ... in a mild downcurrent on a channel dive in the Maldives. She was fiddling with her camera while we were descending down a wall and didn't realize the current was pushing us down. By the time I caught up with her we were at 110 feet and falling fast. Grabbed her arm, showed her our depth, and we started swimming up hard. No telling when she'd have stopped if I hadn't caught up to her ... the bottom was another 300 or so feet below us.

There was some serious conversation going on when that dive was over ... mostly about paying attention to your descent and worrying about your camera once you get there ...

... Bob (Grateful Diver)

 

[supergaijin]

Whenever possible I like to get divers down to a certain part of the reef and just stop. Really stop. For many divers it's actually quite hard as they're used to start swimming straight away.

But it's a great way to get everyone sorted, cameras working, buddy teams established, heart-rate reduced, buoyancy adjusted etc etc.

And you'll be surprised the amount of big fish that come in from the blue to check out what just came down and is making all the racket. If you're swimming straight away, they usually give you a bit of a berth.

 

[sauga]

Wow, that video was painful to watch!!! That said, it took guts to post it. Too often people are so embarrassed or ashamed by their mistakes that they are unwilling to share them; I applaud your willingness to do so.

My guess is that this was posted because you wanted to stimulate our thinking. I am one who believes in "just culture" meaning we are responsible for our decisions and actions, and in assessing others, trying to understand their frame of reference when they act. Its frustrating to hear the comments that assign blame because we don't learn anything from them.

In watching the video and reading the posts, it seems to me that these divers found themselves in a situation they were unprepared for; why?

Were there unusual conditions that day, or were they typical?
Either way, it was up to the dive operator to 1) inform them of the prevailing conditions, 2) provide them with a strategy (mitigating the hazard) to cope with it, 3) what to do if things go wrong. That sounds like an incomplete dive briefing was given.

What went wrong with the divers? Did they over-represent their experience? Were they focused on the dive? Were they preoccupied with where mom was?

As we see in the video, it didn't just happen to one or two divers, so what were conditions like? I for one have never found myself in a strong down current or an whirlpool/eddy. However, if someone told me (briefing) "oh, and by the way, keep an eye on your gauges watch out for down currents" I would be ready and less likely to panic. That said, from this topic I now have a strategy should I ever find myself in one. Panic: absence of a trained response.

This is a wonderful learning experience if we take advantage of it! We have the video and we have the participants willing to discuss it. Lets not take pot shots "You screwed up"; I think they probably know.

Again, thanks for the video, hopefully we can all take a lesson from it.

 

[Sorrows]

Here's the other thread you were looking for:

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

Peliliu was the site of my only truly scary dive experience (and it wasn't anything like this video and other descriptions I've been reading) I should note that I was so nervous about running into the wall or over the wall because of the ripping current, that I swam out...too much. That was when I got taken down and out--I'm a pretty strong swimmer (for my age) so I did manage to fin up and back to the group. If I hadn't, I don't see how the DM could have saved me; it only lasted a few seconds--I guess?--and yet I was so far away, so quickly.

Previously, on a particularly (I think) rough day at Blue Corner, I had overshot and went over the wall, passing the DM. I literally had to claw my way back to get with the group. Though thinking about it now, the DM did not seem that perturbed about it, so maybe that wasn't such a big deal.

I know I'm a big wussy, but although I'd go back to Palau in a heartbeat, no way would I ever try Pelileu again. (Except to visit the battlefield, which is magnificent.)

But I digress. I really wish you guys would decide--once and for all--WHICH is the proper course of action for such terrible and sudden dive conditions! Have we even decided WHAT said conditions were? Whirlpool? Downcurrent?

 

[supergaijin]

But I digress. I really wish you guys would decide--once and for all--WHICH is the proper course of action for such terrible and sudden dive conditions! Have we even decided WHAT said conditions were? Whirlpool? Downcurrent?

As has been discussed in the last couple of pages of this thread- proper reactions to any current is very much situation dependent.

SB has a wealth of information from many experienced divers in different parts of the world- but it remains an internet forum, so I suggest that information here should only be taken as a reference to stimulate 'real world' questions or conversations with experienced divers in your locale.

 

[vladimir]

Peliliu was the site of my only truly scary dive experience (and it wasn't anything like this video and other descriptions I've been reading) I should note that I was so nervous about running into the wall or over the wall because of the ripping current, that I swam out...too much. That was when I got taken down and out--I'm a pretty strong swimmer (for my age) so I did manage to fin up and back to the group. If I hadn't, I don't see how the DM could have saved me; it only lasted a few seconds--I guess?--and yet I was so far away, so quickly.

Previously, on a particularly (I think) rough day at Blue Corner, I had overshot and went over the wall, passing the DM. I literally had to claw my way back to get with the group. Though thinking about it now, the DM did not seem that perturbed about it, so maybe that wasn't such a big deal.

I know I'm a big wussy, but although I'd go back to Palau in a heartbeat, no way would I ever try Pelileu again. (Except to visit the battlefield, which is magnificent.)

But I digress. I really wish you guys would decide--once and for all--WHICH is the proper course of action for such terrible and sudden dive conditions! Have we even decided WHAT said conditions were? Whirlpool? Downcurrent?

One thing I think we are pretty unanimous on is not to dive in conditions that are beyond your experience level. That's the clear message of the thread. It might not always be apparent where that line is, but if you are relying on the divemaster (where was your buddy?) for anything besides a dive briefing then you are a beginner diver, in my opinion, and you should avoid challenging conditions like strong current.

---------- Post added April 27th, 2012 at 08:45 PM ----------

I for one have never found myself in a strong down current or an whirlpool/eddy. However, if someone told me (briefing) "oh, and by the way, keep an eye on your gauges watch out for down currents" I would be ready and less likely to panic.

I frequently dive in Bali these days (well, relatively frequently, but not frequently enough). Especially out on Nusa Penida, down-currents are always a possibility. But I think anytime you have significant current you should assume that there is a potential for down-currents. One concrete step I take is to reserve more gas in my plan than I might otherwise.

 

[hypersonic]

Another thing to consider: If you are going to dive somewhere known for it's strong currents, there is a good chance things are going to be a bit crazier around the equinox.

There is often a lot of discussion on currents. Hardly ever a mention of tides which tend to peak a couple of days after a new and full moon. Couple that with the equinox which drives the tides even higher and welcome to Cozumel the end of March 2012.

The dive date was 03-28. The equinox 03-20. The new moon 03-22.