Caught in a downwell current...

[charlesml3]

Gang,

After the beating I took the last time I posted on NM&LL I swore I'd never post here again. But maybe this will help another diver so I guess I'll take the chance.

Anyway, diving in Cozumel last week and we dropped in at Punta Tunich in a very fast current. I'm an experienced drift diver so this wasn't really a concern. I know how to handle a fast current. Anyway, over the course of an hour, we blew off the end of Punta Tunich, passed Yucab, passed Tormentos and were just at the edge of Chankanaab Bolognes. At the edge of Chankanaab the wall drops off steeply with an overhang and that's where I found myself.

I saw it coming from a few feet away. All of the particulate in the water was welling downwards and there was no time for me to get out of it. I started dropping from 55 feet or so and was at 85 feet pretty quickly. Here's how I handled it:

- I didn't panic. I knew what this was.
- I inflated my BC to suppress or stop the runaway descent.
- I deliberately swam towards the wall.

As soon as I reached the wall the current dropped significantly and I was able to ascend. Dumped the extra air on the way up.

Near Miss: Sure. Could have been a lot worse.
Lesson Learned: Watch that drop-off at Chankanaab when the current is pushing hard from the South.

-Charles

 

[DennisW]

Sounds like you were aware of the problem and dealt with it in a logical and safe manner. I had some friends get off the boat into a downwelling in Cozumel a few years ago. Many of them had to take chamber rides. It was scary and it was dangerous and the operator should have recognized it from the surface and not alowed the dive.

 

[charlesml3]

There's no way anyone could have known we would go that far down-current. This just isn't one of those situations where "the operator should have known."

-Charles

 

[RickyF]

Sounds like you kept a cool head and dealt with it in a great manner! Congrats!!

 

[Scott]

Handled it pretty well I'd say. FYI.....I hate that dive.
Four of us had the same thing happen last year. Only difference is we were nearing 20' for our stop and then we were at 40'.
Guide did not know it was there because he was on the boat 10 minutes earlier.

 

[blue steal]

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.

 

[charlesml3]

but I have read that you should move away from the wall.

Well, like most situations, it depends. The current was running out of the South which meant it was parallel to the wall at Chankanaab. The downwell was caused by upcurrent shelf I passed over. Since this was the case, I moved towards the wall to get out of the wash of the shelf as soon as I could.

-Charles

 

[charlesml3]

Duplicate

 

[RubberDucky]

I did Tunich some time in the last half of June this year, and the current changed halfway through the dive. First it was going backwards, so we had to dive it backwards. Then it switched.

The worst to come was about a week later when the currents were even crazier along the Palancar reefs. They were so fast that planting 2 fingers in the sand to stop yourself was all but pointless.

Then at the airport in Coz for the trip back, I overheard someone else talking about being in a downcurrent. I didn't get any details from them, though I wish I would have.

I'd only ever been to Coz in the earlier months until recently. 4 years and 5 trips later, I finally get it. Coz in June - August is no good. Rainy days most of the time in June, and unsafe diving conditions. I'll stick to the calmer currents and sunny weather of Jan - Apr at this point.

Thanks for sharing your experience. I also would have thought to swim up and away from the wall. Now I'm not sure what the best advice is anymore. I'm trying to picture what you said about the direction of the current in reference to the reef, and the upcurrent and downcurrent, but I can't wrap my mind around it.

How do you see the situation playing out if you had swam up and away from the wall? If downcurrents are similar to waterfalls, you would have escaped from it eventually I guess, but at the same time how can anyone know how "thick" the wall of water is that's pushing you down? I guess you can try to get a visual on ocean matter that's beyond the downcurrent (to see which direction it's going), however feasible that may or may not be.

Crazy stuff.

 

[vladimir]

Thanks for posting, Charles. This one was easier, because you didn't do anything stupid.* Quite the contrary, it seems you handled it quite well. I have been caught in a few down-currents, one on my last dive trip. Sometimes it is evident that they are self-limiting (eg, the bottom is in sight), but they can still raise havoc with your ears, and with your gas reserves.

*not to suggest that he necessarily did something stupid in the incident described in his prior "near-misses" posting.