Improving air use in currents

[Freewillow]

A lot of great advices on this post but I am surprised that nobody talks about the cylinder size.

When you are saying that 12L cylinders are too combersome when you dive, are you talking about Aluminum 12L or Steel 12L? If this is the latter, I agree. Even for me, some 12L short steel cylinder are so heavy in the water that it is a pain, especially at the begining of the dive. Switch to an aluminum cylinder. But my guess is that in Australia you are using aluminum cylinders, right?

Another thing to consider , especially if you become more experienced and go into deeper dives, closer to deco levels or behond, is that you are not alone in the water. In these dives, you have to have enough gas to cover for YOU and your BUDDY, in case of trouble at one's equipment. In these "special" circumpstances, I can garanty you that the SAC (surface air consumtion ) can easily go trough the roof. If on top of that, your buddy is a rather high air consumer, you will soon find out that a 10L or worse, a 8L will be pretty bad.

Diving is a dangerous sport if you are not planning for preventive and corrective measures in the case that something could go wrong. So please keep that in mind

 

[Iralub]

A lot of great advices on this post but I am surprised that nobody talks about the cylinder size.

When you are saying that 12L cylinders are too combersome when you dive, are you talking about Aluminum 12L or Steel 12L? If this is the latter, I agree. ... Switch to an aluminum cylinder. But my guess is that in Australia you are using aluminum cylinders, right?

Another thing to consider , especially if you become more experienced and go into deeper dives, closer to deco levels or behond, is that you are not alone in the water. In these dives, you have to have enough gas to cover for YOU and your BUDDY, in case of trouble at one's equipment. In these "special" circumpstances, I can garanty you that the SAC (surface air consumtion ) can easily go trough the roof. If on top of that, your buddy is a rather high air consumer, you will soon find out that a 10L or worse, a 8L will be pretty bad.

Diving is a dangerous sport if you are not planning for preventive and corrective measures in the case that something could go wrong. So please keep that in mind

Your guess is right, all cylinders I've used were aluminium. I can lift a 12L once its on my back, but I'm very short (about 150cm) and weigh about 45kg, so it's almost as big as me. OK, not quite as big as me , but very cumbersome.

Good point about deeper dives and providing enough gas for buddy. I've done a few dives close to 40m for a short time, but absolutely will not go beyond recreational limits or into deco, and make sure I've got enough NDL time left (using conservative algorithm on my computer). And also won't push air limits (ie. I should have a quarter tank left at end of dive, including safety stop), especially on deeper dives. So in case of equipment failure, there should be enough gas to ascend and do a safety stop, possibly abridged one (I suspect if there is catastrophic equipment failure, I'll consider it a success to get to the surface with a safe ascent rate, never mind a full safety stop).

But yes, very good point that if I am pushing the limits, I will likely need a larger reserve. Perhaps in the future when (if I'm ever) confident enough to do such things. And also a reminder to keep a larger reserve than I may need just for myself.

Thanks Freewillow, I'll certainly keep it in mind.

 

[The Chairman]

The best ways to deal with current are to hide from it, use it, to cheat or a combination of the three.

Currents are strongest in the middle, ergo Don't stay in the middle. Stay close to the bottom, to the side or in the lee of any object. IOW, hide.

Currents can be your friend. Drift dives are the bomb. The boat follows you and life is good. IOW, use it.

Currents can be overcome easily by using your hands. If there is a down line, simply pull and stop your kicking. If there are barren rocks, pull yourself along as it's far more efficient than kicking. In caves we call this pull and glide.

Going slow and getting your trim down are great, but that should be a part of ALL of your diving: not just in currents. DPVs sound like fun and I would love to try them, but then Scuba is part of my exercise regime.

 

[AfterDark]

During my first trip to Cozumel, I noticed that certain folks were particularly better at dealing with current on drift dives. In this case, it was moving more slowly, while I was being blown forward with current all the time, and struggling to stay back with the group, but I suspect it works both ways. As far as I could tell, this had something to do with their ability to take advantage of the topography of the bottom, the fact that the speed of the current is not the same in all places, or at least that's the only explanation I could think of. I'm sure someone here can explain this better.

I'm at a loss to explain it but I use those features of currents whenever I can. In the deep and/or narrow channels I've encountered current going in opposite directions at different depths, using this to extend my dive time is a tactic I've been using for years. At one site I doubled my dive time just by starting at the other end of the channel 10 mins before slack high tide drifting up channel then using depth changes to move in different directions on the way back to the entry point. this also extends my air because I'm using less air at the shallow depths. In spite of that I almost ran out of air on a couple of dives at that site because of the increase in time and the presence of LOBSTERS, mostly the bugs.

In short don't fight the current dive with it. If you can't avoid it than try to plan on drifting back instead of fighting the current on the way back. Then of course there is what most of us in NE do, crawl rock to rock until you can get to a lee spot.