My scariest dive so far.

[Jim Kerr]

WOW! What a great learning thread and scary is an understatement! My adrenaline was pumping the whole time I was reading this. I have not experienced any down or up currents as of yet and I really had not even heard of "UP" currents till now. I will definitely be doing a search for more info on how to get out of those situations. What has already been said here has been very useful. I did not know about "swimming away" from the wall.

And "KUDO'S" to the dive crew! It sounds to me like they were right on top of things. I'll bet you were exhausted by the time you got back on the boat.

I do have some quetions though.

Were you warned by the DM about "down" and "up" currents?

With the horizontal current ripping like you said and taking 15 - 20 sec to get out of the down current how long would you estimate the down current to be? i. e. 100', 200', 500' etc...

Also, how far away from the wall do down currents usually disapate?

What about the "up" currents? How long? Do they go all the way to the surface? etc...

Does anybody know if up or down currents are more common it certain areas or can hey occur anywhere in the ocean?

Thanks in advance!

And another thanks to mow2000 for looking up to see where this dive site was located..

Boy if this was intended for non divers to read I'm quite sure that some of them are thinking twice about whether or not they want to take up scuba diving.

 

[paddyp]

Were you warned by the DM about "down" and "up" currents?

No, the guide was expecting strong horizontal currents.

With the horizontal current ripping like you said and taking 15 - 20 sec to get out of the down current how long would you estimate the down current to be? i. e. 100', 200', 500' etc...

We didn't swim away from the wall so I can't say how far out the down current stretched. It eased off after about 20 seconds. We remained in the same place. We just tried to remain oriented and stop the descent.

Also, how far away from the wall do down currents usually disapate?

I think this is one of those, 'how long is a piece of string' questions. I suppose it would depend upon how much reef the water had travelled over before hitting the drop off, the strength of the current over the reef, or the surface area of the reef top- ie volume of water making the drop over the edge.

What about the "up" currents? How long? Do they go all the way to the surface? etc...

We descended on to a slight sope. The current was running towards the slope from deeper water and was force upwards as it hit the slope. It made it very difficult to descend. I would guess it would travel all the way up the slope to the surface, yes.

Does anybody know if up or down currents are more common it certain areas or can hey occur anywhere in the ocean?

They mostly occur where drop offs occur ie the edge of the reef table. Water flows over the top of the reef and then flows down the wall edge. Up currents I'd guess could occur anywhere there is a slope and possibly at change of tide etc. I'd need to look into this more. If you find any interesting articles, please post them on here for people to read.

If anyone knows other areas that could be susceptible to these currents please post.

 

[Jim Kerr]

We descended on to a slight sope. The current was running towards the slope from deeper water and was force upwards as it hit the slope. It made it very difficult to descend. I would guess it would travel all the way up the slope to the surface, yes.

My main concern with up currents would be getting caught by suprise and getting pulled up too fast causing bubble formations. The way you have described it here, it doesn't sound like that would be the case, is this correct?

 

[diver 85]

Dives like that are avoided by the DM heading down & 'testing' the current before the customers enter the water......otherwise once you're in you have to ride it out, hopefully with good end results.....

 

[ItMustBeJames]

Also, how far away from the wall do down currents usually disapate?

What about the "up" currents? How long? Do they go all the way to the surface? etc...

Good questions to which I haven't found many answers. From my reading, I've heard that a lot of down currents occur where water flowing one way over the top of a wall (e.g. the 'underwater cliff' idea) hits water coming at the wall. Thus, moving away from the wall gets you out of the turbulent zone. This doesn't always help, but it may.

I don't expect that there is any artificial limit to how low you might sink or how high you may rise. It would depend on all of the factors that have generated the down or up current.

Do a search here on SB ... there is a lot of good info on this topic.

 

[Sail 'n Dive]

this thread reminds me of a scary dive in the Quadra Island, British Columbia area several years ago.

I was a newbie diver and traveling alone. I got matched up with a very nice young guy by the boat operator.

my buddy and his friends, a bunch of other guys, were diving nitrox, I was on regular air.

the dive took place very early in the morning, and we were not all wide awake, imho. the dive briefing was given by the boat operator, a local who knew a lot about the area, but who stayed topside. He said, ok, this is a huge wall, and your objective will be to stay at a moderate depth. there is a really strong down current because the tides and currents are really strong here, even at slack tide, and the water peels off the shallow shelf, rolls out and down, and then curls back towards the wall at about 90-105 ft. so if you stay at a max depth of 75 feet, nice and close to the wall, you will be fine, the curve of the falling water is further out at that depth. go down to 90 feet, though, and you will be taking a lot of risks.

being new to dry suit diving,and having only 22 dives under my belt, I decided to be really really careful. but I was having a slow exit from the boat, and my buddy was hanging pretty close to the other guys, and they quickly descended. I hung out at around 30 feet, had a slight dry suit issue, got it sorted out, and turned around to find my buddy. he was quite simply gone gone gone.

I thought, well, ok, what is going on here, I descended a bit more, a bit more, looking around, and thought, well, that was weird, I guess we got separated. I did not really think much about it at the time, I kept looking around and descending slowly to about 60 feet or so, still no buddy, and no group of guys either. not even bubbles.

ok, I thought, I must stay calm, no problem, my gear is working, this is cool, nice wall, keep looking, don't freak out. I gave it a few more minutes, and then did a slow and careful ascent.

did a really cool safety stop, where I ran into another diving party, and I sort of said in sign language, I am ok, but I lost my buddy, anyone seen my group? and they signalled no, but no worries, stick with us, you are doing fine, which was a relief.

finished the safety stop, came to the surface, the boat was right there, and lo and behold, just a few minutes later, there is my buddy and the other guys, surfacing nearby and getting into the boat.

I was sort of shy and new to diving and so I just said, hey, I guess we got separated, just want you to know that I am ok. You see, all along, I thought that I was the one taking almost too much risk being in this diving area in the first place, and I would not have been surprised if he had told me that I was the one who had screwed up.

It never even occurred to me to ask _him_ if he was alright. He looked fine, I was a newbie, and there had been a separation, so obviously I was to blame, right?

Well, blame really is neither here nor there, but here is what happened to him and his friends. I think he saw me get into the water ok and begin my descent. I don't think he saw me slowing at 30 feet and fiddling with my suit.

So then they descended well past 85 feet, pressing right up against and even a bit past the depth limits in the briefing (which were quite close to their nitrox limits too if you think about it.) and it all happened in a flash. It was like they all stepped into an invisible elevator going straight down. The downcurrent dropped them all really fast to a depth of about 135-150 feet in a matter of seconds.

These guys are all built like football players, and they have about 200 dives each under their belts, mostly in places like Quadra Island, in current and tide, with dry suits, often with nitrox. But they could not control the descent or come up. They inflated everything, suits and bcs, and were finning for their lives. By some miracle, the downcurrent eventually weakened a bit.

Then the next risky part -- suddenly all that finning and inflation started to work and work fast. They had enough skills to not get too badly narced, and to dump the air out of both suits and bcs , and to do a controlled ascent. also, they were damned lucky not to experience the toxic effects of breathing nitrox below recommended depth. (maybe they did much later, we did not stay in touch, but they did not seem to be having any ill effects right after.)

Obviously, the moral of this story is: listen to the dive briefing already ! plan your dive and dive your plan !

(one of my dive instructors later said, after hearing this story, there are flashy cowboys, alright, but there are no old cowboys, those guys tend to live fast and die young ...)

 

[marmalade]

Dives like that are avoided by the DM heading down & 'testing' the current before the customers enter the water......otherwise once you're in you have to ride it out, hopefully with good end results.....

as a newbie myself, i think the best thing to do is to hold on to your DM at all times or to have him/her dive w/ you hand in hand all the way. yes,you lose control over buoyancy but would probably end up feeling a lot safer. .

hving read this, i'll make sure my guide/DM/instructor dive w/ me hand in hand at all times...

i'm still young save beautiful. Just don't wanna die young!

 

[ronski101]

I have never used a dry suit (except for water skiing) but I thought that you didn't need a BC when you used one since they provided adequate boyancy capability.

 

[SpaceCase]

Keeping a cool head and implementing your training and previous experience will certainly let you dive another day.

 

[DeNomad]

I have never used a dry suit (except for water skiing) but I thought that you didn't need a BC when you used one since they provided adequate boyancy capability.

A dry suit for WATER SKIING? That seems like overkill... even in Canada.

I'm new to dry suit diving myself, but you don't want to rely on your suit for bouyancy, it is easier to dive if you keep just enough air in the suit to take the squeeze off. If you over inflate the suit you will have issues managing the air space, the bubble will probably end up in your feet, and you will rocket to the surface feet first.

Also, if you have a suit valve malfunction and you have to disconnect the hose the BCD may help with the ascent.