Caught in a downwell current...

[charlesml3]

Thanks for posting, Charles. This one was easier, because you didn't do anything stupid.

I didn't do anything stupid on my previous post on NM&LL but I got called all kinds of names by the "arm-chair divemasters" here.

Anyway, I have a lot of experience diving Cozumel. I know the reefs and currents. With the current running parallel to Chankanaab Bolognes it was best for me to swim towards the wall. I knew what I was getting was a wash down from behind me as the current dropped over the ledge.

-Charles

 

[vladimir]

I didn't do anything stupid on my previous post on NM&LL but I got called all kinds of names by the "arm-chair divemasters" here.

Yeah, I'm not surprised--that was tongue-in-cheek. When I have a "near miss/lesson learned" I'll probably just keep it to myself.

 

[TSandM]

Any time you post a story here, you're likely to get beat up a bit by people who think whatever it was that you did was idiotic. But posting the stories still serves a purpose, especially if there is a learning point for less experienced divers.

This is a perfect example. First off, alerting people that the combination of strong currents and walls can result in up- and downwellings, so you need to be alert for evidence that warns you of them. I think one of the best points of the original story is that the OP spotted the particles moving downward, so he was PREPARED with strategies to cope; in most of the stories I've read from people caught in downwellings, they have not realized that was what was happening until they had already dropped a significant amount.

Second, the story shows that a prepared and calm diver CAN cope with a downwelling. If that's the ONLY thing someone remembers when they run into one, it's still going to improve their chances of coming out unharmed.

And third, we are now discussing the fine points of strategy, including whether to swim toward or away from the wall, or how to "read" the topography to decide how best to get out of the waterfall.

The OP isn't getting beaten up here, but even if he were, those points would still be useful. For that reason, I try to post all my screwups here, no matter what kind of pummeling I am going to take for them.

 

[DandyDon]

Never been caught in a downcurrent myself. I imagine it's like an underwater water fall.
I would also have moved in toward the wall, but I have read that you should move away from the wall.

Depends on whom you ask. One vocal Op on the Coz forum says to move to the wall because you don't know how wide the downcurrent is or to deal with an open water ascent. I don't like going to the wall then up as I know it'll be at the top of the wall when I get to it.

 

[Hatul]

Depends on whom you ask. One vocal Op on the Coz forum says to move to the wall because you don't know how wide the downcurrent is or to deal with an open water ascent. I don't like going to the wall then up as I know it'll be at the top of the wall when I get to it.

Going to the wall also makes sense to me as you can grab on to something and the currents should be slower because of friction with the wall..

On another point it's an argument for heaving some reserve buoyancy in your wing, rather than minimizing it like most like to do.

Adam

 

[RubberDucky]

Having never experienced a downcurrent myself, I'm thinking that if you have a "sufficient" amount of air (whatever that may be at the time), swimming to the wall, then up might be a good strategy. That way you will be at the shallowest point possible when you begin the process of swimming through and out of the downcurrent. Otherwise if you're at 80 ft. and starting to get pushed down, who knows how deep you'll end up before you're actually out of the current? If you get deep enough you're at risk of getting narced (and possibly ox tox, though I know very little about that). If you're "low" on air to begin with, then perhaps getting away from the wall would be best. There's even more factors to consider, such as the amount of air your buddy has, and your ability to remain calm and keep your breathing controlled.

If I had the level of knowledge about the currents that charlesml3 does, the decision would likely be rather automatic. For now I give myself a 50/50 chance of getting it right, should the situation ever arise

It was also interesting to hear about inflating the BC as part of the evasion strategy. I'd read that may give more surface area for the current to push you down, but again the real life experience posted here is what worked beautifully. I guess it doesn't take very long to deflate an inflated BC anyway, so if inflating doesn't work in your favor, just deflate and carry on.

 

[DandyDon]

If you're "low" on air to begin with, then perhaps getting away from the wall would be best. There's even more factors to consider, such as the amount of air your buddy has, and your ability to remain calm and keep your breathing controlled.

I carry a 19 cf pony on the deeper dives at Coz but had left it on the boat to cruise the reef - at the edge of a wall. Suddenly I was at 80 ft wondering why I was so lazy about my pony? Now I ask on the second dive: "Are we going to be close to a wall drop?"

Good luck on keeping up with your buddy in one. If you are as close as you should be, you might go together but often only one gets pulled down. It's like a rip tide on the beach. The ones who fail are the ones who fight. Swim across! With a down current, go to the wall, away from it, or along it to get out but do no hesitate. It gets dark below. :shocked2:

 

[charlesml3]

Yea, it's like most things with diving. There's no one "right answer." DandyDon and I have been diving Cozumel for years and one does develop proficiency after a while. Current/Drift diving is a bit different. Usually it's just a ride along the top of the reef where you only use your fins to keep oriented the way you want to look.

Believe me, I was prepared to try just about anything I needed to get out of that downwell. Had the air in the BC not arrested the descent I'd have filled my SMB next and held onto that. Then ditched weights. It's all about being aware of what's happening and continuing to THINK. Had the downwell become stronger as I finned towards the wall I'd have turned around and headed away.

-Charles

 

[charlesml3]

When I have a "near miss/lesson learned" I'll probably just keep it to myself.

Yea Vladimir, I hear you. I think the prevailing attitude from some of the regulars here is pretty poor. The first thing they do is jump on the poster and make them feel like idiots. Then they come back and ask questions to discover the all-important details. It's what one of the managers here at work calls the "FIRE, Aim, Ready" approach.

Do try to post your encounters here. The knowledge may actually help someone else.

Thanks!

-Charles

 

[Hatul]

I carry a 19 cf pony on the deeper dives at Coz but had left it on the boat to cruise the reef - at the edge of a wall. Suddenly I was at 80 ft wondering why I was so lazy about my pony? Now I ask on the second dive: "Are we going to be close to a wall drop?"

Good luck on keeping up with your buddy in one. If you are as close as you should be, you might go together but often only one gets pulled down. It's like a rip tide on the beach. The ones who fail are the ones who fight. Swim across! With a down current, go to the wall, away from it, or along it to get out but do no hesitate. It gets dark below. :shocked2:

When you travel with the pony do you take the valve off and put in checked luggage?

Adam