Any information on down currents?

[drsmileybee]

I was reading another post and down currents were talked about and it got me thinking. The post said that weedlines might indicate a down current or one near. I don't know anything about down currents. Are they a problem or has anyone ever came by one in the gulf or anywhere else? I don't freedive, only dive with tanks if it makes a difference with down currents.
When we see weedlines, we always stop and get the rods out. I have thought about jumping in and taking a shot at a fish, but now I don't know. Come on with the tales. :)

[FredT]

Downcurrents happen when two water masses converge. The denser one usully decends, and can decend more rapidly than an diver can swim up. A 'weed line" is the top of water remains of a water mass interaction. They are persistant in good weather so the downcurrent may have passed on to other pastures. The floating weeds and debris tend to form a mat that takes some time and weather to disassemble.

The trick to getting out of one is to swim at 90° to the line so you cross the line in the thinest direction to limit your depth excursion. My brother-in law's brother in law died in one in the Bahamas about 30 years ago. He foolishly snorkeled over a blue hole on a rising tide and got sucked down into it. Others have had serious consequences off Coz due to downcurrents, and they are suspected in several disappearances there over the years. Devil's Throat has developed an especially bad reputation. Any time you dive a weed line be aware that they can be possible, and take appropriate precautions.

FT

[MichaelBaranows]

I am glad I saw this post. Cause I have been thinking about do a little freediving around weedlines this summer. I guess I am going to have to be careful.

Michael
Sweeny, TX

[drsmileybee]

Great info. Thanks Fred

[Freedro]

drsmileybee,

In case this is not the thread you were reading, here is a pretty good description of what can happen and how.

http://spearboard.com/showthread.php?t=16306

Be safe,
Eric

[drsmileybee]

I was not aware of this thread but it was good info. Does anyone have any storys of downcurrents in the gulf or Atlantic area?

[Mr. Bill]

I was in the Bahamas last year drift diving on top of a reef where the Stream runs along it. My buddy was carrying the float about 30 ft. above me and I was at about 120 ft. We were moving fast in the strong current when I got to a place where there was a giant crack in the reef that ran down to the first level which was about 200 ft before droping into the abiss. On the down current side of the crack the reef jumped up to about 90 ft where my buddy was flying. When I got over the crack instead of gliding over the higher portion I was hurled down so fast that it seemed that I had no bc and was holding a 40 lb anchor. Even inflating my bc did not stop the fall. At about 170 ft though the current slowed up and pushed me out into the blue. My computer said 176 max. Way beyond the 32 % mix recomendations! I came up and actually had to release air form The bc to slow down. I guess the force of the current against the far wall of the crack pushed water up as well as down and I got caught in the down force. Fortunately I didn't panic as I realized what was happening and knew that I had to stop at the first botom. I did worry about the depth and the O2 mix though. My buddy was more worried that me since I had disappeared so fast from his view.

[IyaDiver]

DOWN CURRENT........ This is one phenomena which I don't want to encounter.

In my country we have location where scuba divers each year die due to this current. Eastern Indonesia have lots of such place.

What I hear from the local dive guides, certain area with a suitable topography and current speed and angle will create a down current.

In the famous island of Bali, there is one location called the Crystal Bay. One very senior diver just lost his life there last year. He knew the place very well and that is how he probably was over confidence. In this place, you must limit your position to certain area only ( i never been there ) and when you passed over to the certain area, the current will suck you out to sea and downwards.

The body of water between Kalimantan ( Borneo to some of you ) and the Sulawesi ( Celebes to some of you ) has a current known as the Indonesian Thorough Flow. I too did not know about this untill I read more because I was curious to learn that some area in Bali and Lombok ( these two islands are next to each other ) in the straightt, in fact a very wide straight, current can approach 6-8 knots here. Many foreign sailors I know have confirmed this.
The Indonesian Thorough Flow is the movement of the water of Pacific Ocean going to the Indian Ocean and my country is in the middle. This area is located on the eastern part of Indonesia.

My friend's uncle only few months back was lost and body never discovered in Alor, another dangerous place where downcurrent we call toilet FLUSH often occurs. A french dive guide i know got once sucked from 120 to 210 feet and survirved while his guest thought it was fun.....fun my a$$ he said.

In the also famous Manado island where the wall dive is spectacular and 300 feet bottom is shallow, I know a few friends who survived the downcurrent. Many were cruising by the wall at 150 feet or so and suddenly they go suck down to 200+ feet. The only thing they could do was to grab the wall's rock and start climbing up like spiderman. BCD maximum inflation is useless here.

The closest encounter I got to a downcurrent was many years ago in Bali where I got to crawl along the sand slope punching my knife to move shallower & forward, it was not that bad, thus I escape OK.

Many years ago I was diving with friends on a near by island by the Sunda straight. The tip of the island at strong current develop a toilet FLUSH pnenomena. I observed the underwater topography before dedicing to descend and I saw pebbles and lots of air bubbles moving arouund. I aborted the descend and managed to make a left turn on the surface to go away from the tip of the island. My two friends continued descend. For some reason, only one was sucked down. He was at 60 feet and suddenly he was spinned and his air bubbles went down. He threw his weight belt and fully inflated his BCD. He did know know where is the bottom or where is the surface, he was in panic. Only a while in the toilet flush and he was thrown out of it to calm water and into the open sea. He surfaced white faced and asked if his nose and ears have blood in them. His depth gauge registered 140 feet as max depth. From that day on, we never want to dive that island tip again unless in no current situation. A few divers been sucked there too but the terrain was not that deep thus no one dies. This island is a bit dangerous, current can be opposite in some spot at the same dive, mild down current is common along the length of the island.

Horizontal current I can live with but a down current with toilet flush capabilty is something I don't want to experience. Usually such pnenomena like the toilet flush can be spotted from the surface. Some slow boats have been suck to this kind of whirpool action and they too got scared. The sudden down current on Manado world famous wall is said to come on only certain months but can not be spotted from the surface.

There is a dive destination book called Underwater Indonesia. There is a story by a world famous lady photographer who got sucked from the shallows of 30 feet or so to 120 feet and popped to the surface. She could not do anything except breath. All happened under 1 minute. She was suprised she did not die of embolism or fractured skull.

At least a few tourist divers die in Indonesia due to down current in the Eastern Indonesia...every year. So becareful guys.

[drsmileybee]

I am scared to get into the bath tub now!

[nyTroX]

I am scared to get into the bath tub now!

Get out of the tub before you pull the drain plug, and you should survive. ;)

[5s Enough]

That's the first I ever heard of down currents, I thought it was only something you would see on "Finding Nemo."
Would you ever see that in the Gulf?

[FredT]

Would you ever see that in the Gulf?


Absolutely!

I've been in several, most of which were manageable with hard swimming and BC assist. The rest were where the swim 90° to the line came into play.

They are most common near a rip, but can happen around significant structure too. If they EVER DO finally manage to drop the Oriskany in diveable waters I'd be careful swimming around it with high fraction nitrox.

FT