Diving Performance - Beyond Drag (article Series And Discussion)

[ronscuba]

Interesting about the dolphin kick versus standard crawl or flutter kick.

Not sure I can see scuba divers adopting it. Seems like it would take a lot more coordination, athleticism and practice to become efficient at it. I also imagine wearing a scuba tank would make learning the kick more difficult.

Maybe step 1 is to improve the scuba flutter kick ? Straighter legs, pointed toes ?

 

[Rred]

The scuba tank and backpack shouldn't be a body cast, a diver should have actually less problems learning a dolphin kick because as they (inevitably) flop around and start to sink, at least they still have something to breathe.(G)

With a flutter kick you create tremendous drag as the vortex from one leg sweeps past the other. No matter how well you kick, that's gonna waste a lot of energy. Of course if you are just poking around...no big deal.

 

[ronscuba]

I don't want to be politically incorrect, but I am having difficulty picturing an overweight scuba diver effectively dolphin kicking.

I will have to give it a try. I'm thin and athletic. If I find it easy to do, I'll ask my wife and dive buddies to try.

 

[REVAN]

PS: Not intended as a dig or insult but wanted to let you know abundance is spelled wrong in the above quoted text. (Let your editor know they need a better spell checker.)

I finally see it; Hahaha! There was a second instance that was wrong. I see now that Cetaceans was also spelled wrong. Weird, because I know that one. Strange that the editors didn't fix those things also. That's life I guess....

 

[Monofin]

PS: Not intended as a dig or insult but wanted to let you know abundance is spelled wrong in the above quoted text. (Let your editor know they need a better spell checker.)

Agreed!

Also, in part 2 "They must be streamlined and may look more like the fusiform shape of cetations than a 4 limed person." Cetations was meant to be "Cetacean" (from Definition of CETACEAN) any of an order (Cetacea) of aquatic mostly marine mammals that includes the whales, dolphins, porpoises, and related forms and that have a torpedo-shaped nearly hairless body, paddle-shaped forelimbs but no hind limbs, one or two nares opening externally at the top of the head, and a horizontally flattened tail used for locomotion.

While fusiform shape is a spindle shape with a round central cross section that tapers to each end, the "Fusiform Fish Shape" (http://www.angelfire.com/alt/fishy/shape.html) implies a roughly equal height and width (streamlined shape) as opposed to Laterally Compressed (flattened from side to side) or Depressed (Flattened from top to bottom) fish shapes.

 

[REVAN]

whether you go monofin or not, I think I would argue that the single greatest change a diver can make is to forget about crawl kicks and go to a dolphin stroke, with the arms tucked back alongside the tank and the feet kicking only in unison.

You will see some monofin style fin stroke examples in the coming parts. You are correct that it is a more efficient swimming stroke and with the right kind of fin(s) it can work with scuba equipment. I've made monofins for scuba diving before and it actually works exceedingly well in my opinion, but I've never been able to get other scuba divers to give monofins a second look. Personally, I think this is a significant oversight. Monofins are awesome and no one knows because they have not tried them, with the exception of competitive freedivers.

For this article series, I tried to keep things looking more familiar. However, this is an example of me scuba diving with one of my monofins:

 

[Rred]

ron-
It won't be easy. Then again, swimming a hundred yards isn't "easy". But if you want easy and one size fits all...I'm sure there's a PADI certificate for that.(G)

 

[wetb4igetinthewater]

Interesting parts. Now, question for the OP. When I'm lugging my large camera around, I'm holding onto it by the most part with both hands. It introduces a lot of drag, so much so that I was once left in the dust by my dive buddies (we were floating in the green so nothing for me to shine my light on for them to see). I noticed in the video that you use your hands a bit. If those are not available, how easy is it to maneuver? I don't see how you would back fin or helicopter turn.

Looking forward to the next two parts, as I am always interested in even small improvements in reducing drag.

 

[mattia_v]

While I'm sure a monofin will improve your speed underwater, I can't say that speed has ever been a limiting factor for the type of diving I do. I spend most of my time moseying about, looking at the pretty, so a monofin? Not so useful for me. Which is probably why most divers don't ever give it a second look.

 

[BRT]

ron-
It won't be easy. Then again, swimming a hundred yards isn't "easy". But if you want easy and one size fits all...I'm sure there's a PADI certificate for that.(G)

Swimming 100 yards is extremely easy if there is no current against you. When I go down and start looking at things I cover hundreds of yards without even noticing the effort. If I had to do it on the surface or in a limited time it would kill me.

We did a shore dive on the East side of Cozumel in February. Surface swam out to about 12' depth in a bay and then swam fairly straight out on a compass heading looking at things as we went. I started with 2000lb of air in an AL80 and at 61 minutes I was at 1000lb and only at 24 feet of depth so I popped up to see where we were. Scared myself silly. We were waaay out there. I could see past all the headlands. We were clear out of the bay. Went back down and swam without stopping much in the opposite direction for 20 minutes and were in 4 feet of water.