Dealing with current

[dmaziuk]

Few divers are even aware what can be done and many divers actively resist the concept of improving hydrodynamics, thinking that it makes no difference. But, there are significant things that can be done to make yourself more robust against unexpected current situations.

I would think if I'm in un-diveable current, the way out is up anyway. At which point my hydrodynamics makes no appreciable difference.

Ability to outswim the guy next to me might come in handy during a shark attack, I'll grant you that.

 

[REVAN]

At which point my hydrodynamics makes no appreciable difference.

LOL - That didn't take long. I told you this was the mainstream attitude. Maybe you all should dive without any fins. Afterall, hydrodynamics makes no difference, so why bother with them at all.

 

[dumpsterDiver]

I would think if I'm in un-diveable current, the way out is up anyway. At which point my hydrodynamics makes no appreciable difference.

Ability to outswim the guy next to me might come in handy during a shark attack, I'll grant you that.

The ability to move or swim against a current (and make it back to an anchor line or mooring) can be the difference between a strenuous dive versus a cluster that ends with a dive boat searching for you for an hour, you drifting off and then having to climb the "ladder of shame" in front of all the other divers who can't do their second dive because you wasted the captain's time.

Of course, you should never put yourself in a situation that you have to muscle your way out of, but even I'm not perfect..

 

[REVAN]

@billt4sf : Given your location, you may want to look into some full foot fiberglass long fins from DiveR in Australia. They make excellent fins.

I make some really nice high performance scuba fins, but I'm in the USA. DiveRs are great. I've got no reservations recommending them for performance diving. They are not cheap, but in this case you will get what you pay for.

 

[TMHeimer]

All good advice from the experienced. If my simple shallow shore diving involves tidal current (such as inlets), of course I go for high slack tide or a bit before. If unexpected current, I grab the nearest rocks and head to the closest shore. Pull myself to the exit, or exit wherever possible (and deal with maybe a long walk). Planning more than one exit point is a good idea.

 

[dmaziuk]

The ability to move or swim against a current (and make it back to an anchor line or mooring) can be the difference between a strenuous dive versus a cluster that ends with a dive boat searching for you for an hour, you drifting off and then having to climb the "ladder of shame" in front of all the other divers who can't do their second dive because you wasted the captain's time.

Of course, you should never put yourself in a situation that you have to muscle your way out of, but even I'm not perfect..

You write it yourself: you cannot swim against a significant current for any significant time. I fail to see how super-streamlining would offer me significant advantages against insignificant current and/or over insignificant time. Yes, you better have the muscles and fins, but most of all, as again you yourself say: the smarts to grab on to something and crawl rather than try to out-swim the ocean in the first place.

I come up from my average dive -- not a niagara falls surge disaster, just the regular splashing around a reef -- with around 1K PSI in Al80. If due to my superb hydrodynamics I come up with 1009 PSI instead of 999, well, forgive me for not really giving a toss.

 

[The Chairman]

You guys work too hard. I Scuba smarter, not harder. All this hoopla about kicking efficiency is like putting wax on a minivan in hopes of improving fuel mileage when it comes to dealing with currents.

Drag increases exponentially. Muscle efficiency decreases exponentially. Like putting lipstick on a pig, trying to out kick mondo current is a loser's proposition. Remember the five important steps to playing Dodge Ball because they work when dealing with current too...

Dodge, Duck, DIp, Dive and Dodge!

​

 

[REVAN]

I come up from my average dive -- not a niagara falls surge disaster, just the regular splashing around a reef -- with around 1K PSI in Al80. If due to my superb hydrodynamics I come up with 1009 PSI instead of 999, well, forgive me for not really giving a toss.

The issue is not just the regular splashing around the reef kind of dive, the issue is what happens when the current cranks and the dive has a strong potential to turn into a cluster that you regret getting into. The less capability you have to swim in your scuba equipment, the more likely you will be to end up in one of those situations.

Average ocean currents are in the range of 2 to 3.5 knots. That's about 2 to 3.5 times faster than most divers can deal with at their absolute best. Statistically, we must restrict our diving to only the very best ocean conditions that represent about the bottom 1 sigma of the bell curve for the distribution of ocean current speeds. For an arbitrary location, about 97% of ocean conditions are not really good enough for most people to plan on conducting a dive in without external help and/or being tied to the surface in one way or another, and there is a high probability that that the conditions will deviate beyond what is expected leading to a bad dive. If you can double your effective swimming speeds, that 97% will drop to something more like 83% chance of bad or un-diveable ocean conditions. If you can handle on the order of 3 knots you can deal with the statistical average meaning you've got about a 50/50 chance of being okay in a randomly selected location. Add some planning to the situation to attempt to get good conditions and the likelihood of a bad dive can drop to a very acceptable level. At about 6 knots, you'd be okay in about 97% of all ocean conditions.

The statistics of this are not linear, and divers typically operate at the worst edge of the non-linear curve giving them the worst odds for a good dive outcome. This is why performance matters.

Presently, we are placing our lives in the hands of those making the decisions for where and when we dive with the odds of the statistical spread of ocean conditions stacked heavily against us. People can be smart and with good observations cherry pick what dives to do and have a very long streak of good luck. However, when you pay to go out on a dive boat and the captain determines where and when you dive, you only have veto power to sit out a dive that you have already paid for. In those conditions, I suspect many divers will be inclined to trust the captain's judgment and go for it. The divers most at risk are those with the least experience. The OP's story shows that this situation does happen, and it is not just a once in a lifetime fluke (unless it tragically ends in the diver's death of course).

 

[lerpy]

I dive current all the time, I find the best approach is to roll with it and enjoy the ride, but I guess that depends on location. I dive in a river primarily so although the current is swift, pick up the drifters is not that difficult. Big thing is carry a nice big sausage, like a 6 footer so you can been seen by the boat picking you up. Current can catch you off guard, and I have seen many people come dive the river that sometimes ignore warnings of strong current as they have dove in current like on Coz before. The current here is often significantly stronger, my advice is listen to the guys on the boat, and hold the line when you hit the water, and be big enough to climb back out if the current is causing you concern.

 

[The Chairman]

Drift dives are fun and easy. You don't have to worry about how big the current is at all. It's while diving off of an anchored or moored boat that it becomes an issue. In that case, the immortal words of Patches Hoolihan are the best way to deal with it:

Dodge, duck, dip, dive and dodge!