Currents and diver experience level

[peterbj7]

Quero has as usual covered the issue pretty thoroughly. I'll just add one point - knowing what to expect underwater can be very helpful on a fast drift. I remember drifting at 5 knots off the west of Scotland, and although I had a certain amount of manoueverability the visibility wasn't that good, and by the time I saw anything it was too late to avoid it. So tucking my hands and feet away and ensuring I remained vertical (to protect my head) were prime considerations. Get a thorough briefing from an informed local.

I've never been caught in a down current, but I've seen it happen. Two divers who had chosen to ignore a thorough and very clear briefing went too deep at Ras Mohammed in Egypt and were caught in a severe downcurrent. When their rescuer caught up with them they were at 58 metres and still descending fast, totally oblivious of their situation. The rescuer was a highly experienced instructor friend of mine who was diving Nitrox 32% and put her life in great jeopardy. Had it been me I would have left them to their fate - it would all have been over within 5 minutes.

 

[TMHeimer]

I've never done real drift diving nor experienced those upwelling and downwelling currents. They do sound scarey. I have done a lot of diving in and around the inlet openings to bays on the Gulf Coast. Local advice is good. Going at the proper time (just before to just after high tide) is good. Trusting that the Gulf tide predictions are always accurate (diurnal tides) is not. The only piece of advice I can add is that if the current seems to be getting too fast too quick stop and think about your best way outta there.

 

[Bigd2722]

Additionally, the more dives you have, the more familiarity you have with your gear. At 20 dives, I was still just getting used to where things were and which button did what,etc.

 

[Mayor]

I find trim to be very important in drift diving. I can use my body to adjust speeds buy creating more surface area or less in the water. The same would be true when fighting a current. I'm as slick and clean as possible which allows me to work much less. Most divers create a lot of drag and spend most of the dive fighting against the flow rather then working with it. Also having streamlined gear with clean propulsion tecniques makes things much easier.

 

[dumpsterDiver]

I find trim to be very important in drift diving. I can use my body to adjust speeds buy creating more surface area or less in the water. The same would be true when fighting a current. I'm as slick and clean as possible which allows me to work much less. Most divers create a lot of drag and spend most of the dive fighting against the flow rather then working with it. Also having streamlined gear with clean propulsion tecniques makes things much easier.

I'm not sure I understand how the physics work with your description of DIR diving in a current. Can you supply a little more detail of how your body position would affect the speed with which a current carries you?

 

[Mayor]

I'm not sure I understand how the physics work with your description of DIR diving in a current. Can you supply a little more detail of how your body position would affect the speed with which a current carries you?

Not really a DIR thing but I have found staying in a streamlined position my speed is much slower. For example if I wanted to increase my speed I would break trim slightly and create more drag. Also moving my fins slightly in the flow can adjust what direction I'm facing. This becomes very cool going backward in the flow ( just check behind you now and then). These are just my observations in a strong current (drift dive).

 

[dumpsterDiver]

Not really a DIR thing but I have found staying in a streamlined position my speed is much slower. For example if I wanted to increase my speed I would break trim slightly and create more drag. Also moving my fins slightly in the flow can adjust what direction I'm facing. This becomes very cool going backward in the flow ( just check behind you now and then). These are just my observations in a strong current (drift dive).

If you are drifting with the current (as in a drift dive) then your speed relative to the water would be zero. When your relative speed is zero, then drag is zero. I think it is impossible to modulate your speed in a current by changing your orientation to it.

 

[supergaijin]

Diving and driving has many analogies which can be used to describe different situations.

I liken diving in current to driving on the highway. The speed involved requires the diver/driver to have all the basic functions down pat so that they aren't being task-loaded when something unexpected happens.

For example, divers who have experience are more likely to feel pressure differences in their ears to judge whether the current is pushing them up or down and can take immediate steps to correct themselves, such as a deeper breath or small kick.

Beginner divers have so much task-loading already that they often don't even hear tank-banging from the guide. Another example is that they are not yet in tune with their equipment to sense the difference in behavior of BCDs- the sense of lifting under the armpits which should require a deep exhale, or deflating of the BCD.

 

[Mayor]

If you are drifting with the current (as in a drift dive) then your speed relative to the water would be zero. When your relative speed is zero, then drag is zero. I think it is impossible to modulate your speed in a current by changing your orientation to it.

Again this was my observation in the water diving with a group. I'm sharing my experence, right or wrong it was very fun diving.

 

[scubafied]

There has been a lot of good advice given here so far. Just wanted to give my insight about 2 of the spots that were mentioned. I lived and worked in Bali for 6 months last year. Nusa Penida can be a great time but if you have no experience in current I would suggest trying out spots where the current is slightly more predictable first. As mentioned, some ops require a certain number of dives or certs to go to certain spots and this is all highly relative as you have no idea what kind of conditions those dives were done in. Manta Point is actually not a bad dive, rarely any strong current but quite a bit of surge you'll have to deal with. Crystal Bay is probably one of the most deceiving sites I've ever been too, (besides Blue Corner). It sits in a cove with a small island helping to block some of the HEAVY current that is pushed through the channel just outside the cove. In my 6 months there 1 person died from an OOA/Lung overexpansion incident and 2 others were swept away at depth and to my knowledge still have not been found. You can splash with absolutely no current running along the island and half way through your dive all hell breaks loose with current going every direction imaginable and people are holding on to anything they can. It's a site many people wish to dive so they can see Molas but they don't realize that fish that big hang out in some pretty ridiculous current. I watched one of my fellow instructors chase a guest down to 50 mtrs and pull her off the ledge she was about to go over that dropped to 200 or more. Upon surfacing she said she had no idea she was that deep because she was chasing a Mola trying to get it on film, hadn't checked her computer and thought because everything was so clear that she was still relatively close to the surface. If you go just remember to keep a close eye on your guide and what he's doing and if you've got a camera make sure you can clip it off because you may be needing both of your hands.