Cool looking bifin

[iceselkie]

This looks really cool.. Have you seen this style before, and how does it feel?

[cantshoot]

Wow, cool looking

I wonder if it works as good as it looks.

[spaghetti]

Effesub Whalebone: italian stuff. The two half-blades are in carbon: with the red cursor on the "bone" you can adjust their cabapility to flex. They're new: I dont' know anybody who has tried thm.

[SEDATE]

Cool looking Really!

[trux]

Originally Posted by spaghetti

... The two half-blades are in carbon...

Actually not, the manufacturer's website claims the blades are made in Polyprophylene. I see them on the italian eBay. The seller claims they cost €115 in retail.

I'd be curious about a review, and also be interested about the expected lifetime of the slider - it looks pretty fragile on the first look

[Yidaki]

Split blades for my opinion is useless however this one has cursor, so, a bit changes the situation, Also, cut out on the blades remind me Jacques Mayol's red fins in Big Blue(Le Grand Bleu) movie.

[trux]

Originally Posted by Yidaki

Split blades for my opinion is useless ...

I am quite the opposite opinion. I personally tried several scuba split fin pairs and although I was extremely sceptical about them before the try, I was very surprised about their efficiency and impact on the oxygen consumption, afterwards. Well, in fact, only the first type (Scuba Pro Twinfin) was remarkable, the second split fins I tested were just a bad copy not propulsing correctly (I do not remember the brand, but nothing well known) - so of course, not all fins cut in the middle will profit from the propeller effect. The fin must be really well made and well tested before finding the right geometry to give good results. And I firmly believe that once a good freediving splitfin is made, it brings new records. Maybe not so much in depth disciplines, but I am rather sure at least about dynamic apnea.

We already discussed the propeller effect of splitfins in this thread.

However, this Whalebone fin, although it has split blades, does not use the propeller effect of split fins, just because of the slider connecting the blades over the very stiff middle "whalebone". I think this way still can be rather efficient, if it is done properly, but it is the opposite principle of the split fine. Classical split (propeller) fin channels the water through the blades inclined diagonally in the direction of the middle gap and continually and progressively bent in the length (see the pictures below). Unlike this, the split blades at the Whalebone fin will bend in the outward direction - I think it can still have very positive impact on the turbulences, but the overall efficiency certainly very much depends on many factors. That’s why I wrote I'd love to see a review and good comparative tests made by independent testers.

[Yidaki]

maybe just for me they r useless, after many years competetive cycling, most of fins that I tried did not convince me,,. When I first try Scubapro twins definitely with the heavy scuba equipment at the depth I couldn't get enough pushing force..They were look like paper underwater,.. So, always looking for stiff blades..Never think about free diving versions though.
Even my custom made blades generally stiffer than market, so that enough force to put..
As a result, maybe we should state for personel requirements to use,..But once again I don't pay peny to them...

[Jon]

No Yidaki, it's not just you.

I have posted on here, and other places, many times my opinion on split fins- They SUCK!

I've tried them and was NOT impressed in the least. If you want a soft fin then buy a soft fin- not a broken one. To me they felt like force Fins- but at twice the length and only half of the useful traits.

I've used them for scuba diving, tech diving actually, and underwater hockey. People show up with these things and wonder why they can't move to catch a puck. Give them a cheapo pair of snorkel fins and they can wipe the pool compared to the Force Fin/ splitfin crowd. I simply don't buy any case for incresed propulsion with them- and don't get me started on line entanglement problems with them.

The other probelm withthem, besides the suck, is that they are WAY too expensive. You can get a decent pair of fiberplatic freediving fins, in a range of stiffnesses, for less money!

I do feel that people need to match the fin stiffness to their leg strength, but this is best done by purchasing the correct blade stiffness/ material. there are many companies to choose from in this regard.

Split fins are just more dive industry crap to try and sell to an unsuspecting newbie.

Jon

[Fondueset]

So, jon; what do you really think?

[trux]

Originally Posted by Jon

Split fins are just more dive industry crap to try and sell to an unsuspecting newbie.

Yes, that was exactly what I told to my friend who bought them once.

That was until we went snorkelling together one day and I simply could not keep with him although I am much better swimmer and diver. I was shocked. I then tried them and agree that they feel extremely soft, like if you have no fins on your feet at all. But although you do not feel it, they indeed propulse better than comparable plain fins. You have to change your kick though - you have to use quite short, relatively quick, continuous kicks to have them working properly.

I agree that they do not accelerate well. I would never consider them for UW rugby or hockey, spearfishing, or for depth freediving disciplines. And although I would not even consider using these currently available split fins for recreational freediving or for competitive dynamic apnea, once there are splitfins specially made for freediving, I bet they can help increasing the performance. The available models are simply nothing even remotely comparable to freediving bi or monofins, but it is just because the fins were made for scuba, not for freediving. And I believe an efficient freediving splitfin can be made (at least for DYN).

So my conclusion is that splitfin is not a commercial crap. You cannot take a scuba model specially made for reducing your O2 consumption during scuba trips, and expect they can perform in completely incompatible disciplines like UW hockey or deep freediving. They do their job quite well though - I was not the first sceptic who had to admit it. Many independent testers confirmed it too.

However, I admit that they are not suitable for everyone even in scuba. In spite of the advantages, some people simply do not like the softness, are not able or willing to change the kick, or cannot live with the reduced acceleration and manoeuvrability of the fins.

[Jon]

As I said at the start of my post I DID try them for scuba and they were crap.

When on scuba I frog kick, so as not to stir up silt, and they just don't work as well as a normal paddle fin. I've also used them at depth with a set of twin 108's on my back and a couple of 80's under my arm and they were even worse than force fins and no where near as good as my Jetfins or Turtle fins.

You can buy a much better fin for less money and use the extra cash for something good- like more gear!


Jon

[trux]

Originally Posted by Jon

I've used them for scuba diving, tech diving actually, and underwater hockey

Originally Posted by Jon

As I said at the start of my post I DID try them for scuba and they were crap. ... When on scuba I frog kick,...

I think it would be fairer to choose the words more carefully. I do not think it is correct to tell about the fins they are crap just because you used them in wrong way and for wrong purposes. Using split fins for UW hockey or for technical diving surcharged with load, and additionally using frog kick, is certainly nothing they were designed for.

The split fin propeller principle is definitely not a crap. If you use the fins correctly (low amplitude short quick kick), they are very efficient and reducing your oxygen consumption noticeably. You pay for it with bad acceleration and worse manoeuvrability in comparison to strong short wide scuba fins. It depends on your needs, on the diving type, and on the situation, to decide what is more important to you.

So although I fully agree that split fins (at least those I know, but more likely in general) are not suited for UW rugby or hockey, for cavern diving, or for diving with heavy load, or any other situations requiring strong acceleration or excellent manoeuvrability, I resolutely deny that they are crap if used for purposes they were designed for. And as I already stated, I believe and hope that once we see good split fins specially developed for freediving, we can see nice increase of DYN performances. Personally I'd tell that dynamic apnea is the exact diving style that can profit the most from the split fin propeller effect. But of course, trying DYN with scuba split fins is nonsense, and so far there are (AFAIK) no real freediving splitfins available.

Maybe even the whalebone fin that started this thread can work well and I'd be interested in testing it. I am just little bit afraid of the lifespan of the slider. From the picture it looks like it can break away after the first really strong kick, but I may be wrong of course. I'd love to hear from someone already using them.

[Jon]

So although I fully agree that split fins (at least those I know, but more likely in general) are not suited for UW rugby or hockey, for cavern diving, or for diving with heavy load, or any other situations requiring strong acceleration or excellent manoeuvrability


That pretty much sums up 90% of diving!

Anyone who has taken anything beyond a basic openwater course should know how to do more than one fin kick, and even on a basic flutter I can move better with a paddle fin. Frog kicking is not just for cave/wreck/ tech diving. I find it most useful for single tank reef diving where I'm shooting pictures. My wife, who only dives warm water, only uses a frog kick since that what gives you the best mobility without trashing the reef.

Besides frog there are also backward kicks, shuffle kicks, dolphin kicks, modified flutter kicks which all benefit from having a regular fin that hasn't been spilt up the middle and creates extra turbulance by having it's bits flapping around- which is one of the main reason why monofins are more effcient than bi-fins to begin with, less turbulance.

So I guess you would recommend these fins for someone brand new to the sport with little training and doesn't want to take the time to learn how to dive properly or buy a cheaper fin that works better in a much wider range of areas. If someone just had to have an overpriced pair of fins that only worked for flutter kick they would be better served by buying a pair of force fins- since you can praticaly play basket ball in them and they make dive boat ladders a breeze- but still suck for all other typesof diving.

If your diving current (think Cozumel, Palm beach, South end of Curacao, the Blue Corner of Palau) there is nothing better than a pair of freediving fins- just be sure to get the correct stiffness to match your leg strength, or lack there of.

Jon

[Amphibious]

Originally Posted by Jon

Split fins are just more dive industry crap to try and sell to an unsuspecting newbie.

Jon

Split Fins.... Spare Air.... buddy Lines.....