Comparative advantages

[jrtonkin]

Mostly a curiosity question, but I'm trying to find out the relative merits of different fin types. I'm explicitly not looking for the "best" fins, since the definition of best varies according to what's important to the user, however, for the following catagories (or any other ones I miss) which fins do the best or worst job for that particular catagory (even if they suck at everything else)?

Absolute top speed?
(Not that I can see a need for it for scubadiving, but hey, it might be important to some people, and it's a perfectly valid measurement)

Lowest effort for high speed?
(Which could be important for free-divers, or if fighting a current)

Lowest effort for moderate speed?
(From what I understand, this is the area that split-fins excel at)

Highest acceleration from stopped?

Best for cornering / sudden direction changes?

Lowest wash?
(Important in silty environments, or if in close proximity to a reef)

Most versatility in terms of kick-styles?
(Which I think is the big claim for JetFins)

Highest thrust at low speeds?
(Could be critical in a rescue situation, where you had to tow a diver; or if you had to pull a whack-load of non-streamlined gear)

All this just for the sake of curiosity...

Jamie

 

[leadweight]

Several publications have been involved in objective fin testing over the last few years. It is an involved topic to say the least.

http://www.ndsu.nodak.edu/instruct/grier/fins.html

You also might want to look at the above URL. It is a fin test done by a scientist who participated in the fin testing done by Rodales Scubadiving magazine. (Also checkout divernet). One of Grier's conclusions is that there is a correlation between various measures of fin performance including top speed, static thrust and air consumption.

The bottom line is that full foot fins usually outperform adjustable fins in controlled testing. The only adjustable fin that seems to consistently outperform all other adjustable fins in controlled tests is the Apollo Pro. In Grier's test the top three fins were full foot. Some of the worst fins were open heel versions of the same full foot fins that were superior. In a recent test in Rodale's a group of cheap snorkel full foot fins (all conventional design) blew away a field of adjustable fins of various designs. However, some of the more flexible snorkle fins may have short useful life when used for scuba diving.

On this board there are many DIR divers. Their view is that the Jet Fins, or one of its many variants when equipped with spring straps are the ultimate. However, this is based on diving a fin in cold water with dry suit boots in an enviornment where a modified frog kick must be used to avoid stirring up the silt on the bottom of wrecks and caves. Most of the new desigh fins (especially split fins) work best with a flutter kick.

To further confuse things many divers report that split fins are poor performers when swimming against a current. Photographers generally do not like the split fins because they don't work well for holding a position or sculling.

In the USA many popular full foot fins are not available. A lot of this is marketing. What would you rather sell, a patented split fin for $200 plus a $70 pair of booties or a $50 full foot fin that blows the former away.

If you mainly dive in cold water or do shore entry from rocky areas, full foot fins are not an option. For those who dive from boats or sandy beaches in water 73f and warmer, full foot fins offer unmatched comfort and performance. You can go colder with neoprene socks if the fins are sized with a bit of extra room. I can say from experience that divemasters working on boats in warm water areas usually use full foot fins. The Mares Quattro Power fin enjoys a hot reputation among these types.

 

[dotyj]

Take this with a grain of salt since I'm still really new at this.

I really like the ScubaPro Twin Jet split fins I've been using since I started my scuba classes early last month. They're really easy for me to kick, I can move around pretty well for a guy who has a lot to work out yet in buoyancy and trim.

I'm sure though that there are better fins on the market, but I really do like the ScubaPro Twin Jets.

 

[Ber Rabbit]

My LDS owner was informed by his split fin rep that people who cannot be broken of bicycle kicks do well in split fins. The guy said if you absolutely cannot get someone to flutter kick put them in split fins because the bicycle kick still provides thrust in that type of fin. The owner said he hasn't had the chance to try it yet but it sounded logical to him.
Ber

 

[Walter]

Force fins also work well with a bicycle kick.

I've never seen anyone I couldn't break of that kick before I put them on SCUBA. Some will revert a few times, but keep working, they'll get it right. I would never substitute different equipment for proper technique. If they can't master the skills, they don't get certified. Proper skills includes all the kick styles I teach. Bicycle kick is one I don't teach.

Back to the original question. In my opinion, Jet fins are top of the line in all areas except one. I prefer much longer fins when free diving.

 

[Ber Rabbit]

Unfortunately I've met a student who cannot seem to get the flutter kick down. He says it makes his legs tired but what's actually making him tired is the fact his whole body goes rigid when he concentrates to do the kick. His arms move in little robot motions and his legs only get about a 3 inch movement up and down then his mask floods because he squints his whole face up while trying to do the kick. He's actually very proficient using the worst bicycle kick I've ever seen, he actually bends his knees almost all the way to his stomach. We don't teach the bicycle kick either, for OW we stick with the flutter and the dolphin but mostly the flutter. Since this student can't be certified due to a medical condition anyway I decided to make the class enjoyable for him and quit harping about the kick a long time ago.

I too enjoy my jet fins, they're still the best fins I've ever tried.
Ber

 

[Walter]

Ber,

We can discuss this if you are interested. Perhaps in another thread, in PM's or on the Instructor's forum. I think he'll enjoy the experience more if he gets the kick down. The other issue to consider is - if he has medical problem that prevent him from being certified, should he be on SCUBA at all?

 

[MikeFerrara]

Instructors forum?