Hi Krusher, I get what you’re saying about the ‘ Da Fin’ presence in Hawaii, they prolly made a deal to supply the Lifeguards and buy pro endorsements that are impressive, but it doesn’t always equate to public popularity, even tho that’s the aim of endorsements.
Same with modern bodyboarding fins, certain companies made it their business to dominate the sport since the 80’s and with amazing sales at that time, they looked to be the fin answer for most.
However, it always comes back to repeat sales. Someone can have a pair of Churchill’s in their garage and proudly drag them out 40 years later, but if they didn’t like them in the 80’s , they prolly don’t like them now and they might’ve hung on to them because they’re not cheap. I hate throwing out crap even if I hate it because I’m hoping something will change and it’ll become useful one day. Much like all the crap in my garage.
Repeat sales are the best indicator of whether a fin is successful. If you’re Da Fins were lost , would you buy another pair ?
Sure you’d buy a replacement for a lost fin because you’ve already got 1/2 the set, but if you lost both…
Would you immediately buy the same or look for what’s new ?
After 25 years of trying out various fins, I have now repeat bought The MS vipers several times. Initially, I was buying the yellow dot stiffer pairs, but found after walking in and out of the water across sharp rocky reefs they would eventually crack across the foot pocket (this is use and abuse on my part) after a couple of years of heavy use, I then bought a pair of the orange dot, which i find easier on the legs being softer (more flex like a fish’s fin) and they have survived the rock abuse for much longer.
I had a pair of dafin and after less than 10 surfs they snapped across the heal straps (which are the thinnest heal straps I have seen on a fin) a few years later I won a set in a comp and gave them to a friend he lasted less than 5 surfs before they snapped too. I would no trust them as a lifeguard fin, if the straps snapped which in a rescue it could mean someones life.
In my head I keep going back to some sort of attachment to the shins instead of feet. What if there was some sort of shinguard/shin wrap that wouldn’t spin around your leg but actually look like an asymmetrical fin? Do they need to be on your feet? Your legs seem to be doing a lot of work when kicking but the feet, not so much IMO. Please see the image. Once you stop laughing at my terrible graphic, you can see what I’m trying to get at. If it was possible to get desired propulsion from these ShinFins™, you would be able to use them to catch a wave and then stand on your board. No guarantee you wouldn’t be laughed off the beach though.
I won’t laugh at your graphics skills, they are far superior to mine. As much as I think your idea eliminates the pocket/foot issue, the physics of a fin at the end of the foot would seem to be more likely to generate greater propulsion, than a fin attached to the shin. I looked into improving technique a while ago and contacted Rob Case from www.surfingpaddling.com/ who offered the following suggestions, which I thought some might find of use.
"The finning technique depends on how long your blade is. You kick a lot different with a freediving fin than you do with the typical bodysurfing/bodyboarding fin.
However, there are some common fundamental kicking techniques across all:
Use your whole leg – initiate the kick from your hip flexors, let the fin build up the water’s resistance on the blade, and then release it. I like to imagine my blades grabbing and then whipping the water back.
o Be careful of too large of a kick. Since we are always trying to minimize drag, if you kick too low or too high, meaning the foot is raised higher or lower than your body and board, then you are going to adding drag.
· Thus, small quick kicks are used when sprinting and slightly longer draw out kicks are used when paddling/kicking back out. But try and keep the kicks within your horizontal profile (what you look like when you are viewed from the side at the waterline.
· Point toes is also a key technique as well as kicking on the up AND down stroke (use your quads and hamstrings)"
I always prefered Duck Feet to Churchills because of the power they had. That works against someone who hasn’t used fins for 15 to 20 years. I played water polo in high school and many of my contemporaries became lifeguards here, a lot of them used Churchills when we body surfed. Mark Cunningham was a strong supporter of Da Fins, he’s a few years older than me and played water polo for our rival school. Whatever works for the lifeguards is good enough for me, but I rarely use fins these days, so I think I’ll need to put the time in and get my legs back in shape.
It’s like paddling - you can get out of shape easily. With your background it will come back. A small fin would be better if you want to use it to body surf back in. I had read once about a guy who kept a pair down the back of his shorts - can’t see how comfortable that would be. You’d also have to consider how easy or difficult it would be putting a pair on, in the water.
Surrfoils once made me a small inflatable mat, that would fit in a pants pocket or small bag and could be inflated to catch waves in on.
So my theory is that a flipper works by moving thru the water at an angle and that pushes the water back and the wearer forward.
Obviously the more water going backwards the better you move forward but fins are basically a flat plate with lots of sideways washout.
daFins have a small vertical ‘horn’ more than a strake up near the foot but a Scubapro fin has a pronounced curve edge near the trailing edge and these fins get rave reviews about their drive.
If you take an average flipper blade of 45 sq in and guess there’s a loss of 30% due to sideways washout and vortices then potentially it’s possible to have the same drive or higher from a small fin due to higher efficiency.
Maybe the loss of drive due to a flat blade is higher than 30% , it could be 70% .but you don’t want a larger blade as it’s more tiring to use but a more efficient blade would have a similar feel as it’s channeling more water rather than slipping thru it.
I have seen guys surfing with a fin stuffed in their shorts, usually on bigger days. It’s not a practical way to do it. I used to wear reef walkers and walk out on the reef at low tide. Once I got out into the water I’d stuff them in the backside of my shorts because I didn’t like the way they felt riding my board. One bad wipeout and their gone, or one is gone.
When I was growing up my family had beach front lots where we all learned about the ocean. We used to ride waves with anything we could think of. One time used large heavy duty trash bags once to catch waves. You just swim out with the bag deflated, then fill the bag up some and twist it closed making sure you have a good grip on the twisted end to keep the air in. It was a poor man’s air matress, and worked until the bag popped. We used fins for better propulsion, but if the bag was filled up enough, the wave would catch you.
I found some silicone pockets that fit my foot and with a little add ons, it can become a soft fin that I can fold up enough to put in my pocket while I surf. I’ve thought about something that I could wear while surfing, but I think it would be hard to get used to. Truth is that if I just got my swimming back to where I could catch waves easily, I wouldn’t need anything, but I don’t think that is going to happen, I’m too lazy.
Looking at the peak of fin design over the years, Churchill’s, UDT, Vipers and DaFin they all have a stiff blade and are made for fit riders, that’s where the drive comes from. And irrespective of the fins performance, the fit and, comfort seems to be even more important. A generous foot pocket especially across the toes and a robust heel strap, as Krusher said the DaFins are a bit thin.
I think there’s room for a collapsible, inflatable, folding fin Sharkcountry,
Cool shots. One thing about using alternative wavecraft is often there’s very little control, but that was how things were back then. It was all about the fun, the thrill of sliding along. It’s a drug, catch a wave and it feels so good you have to get another, and another, until you have that bad wipeout.
These are the paipo boards I’ve made in the last 2 months. The first one I did was copied from a wooden paipo I saw at Inter-island Surfboards. It has the old paipo nui outline, but the nose is fairly flat and the tail has small turned down rails. It is 25 inches at the widest part, 40 inches long and about a half inch thick. I rode it only once and had a hard time carrying it down the cliffs to get to the beach because of the width.
The blue bottom board was made next. I used an EPS blank of an alaia I had made years ago. I cut of 40 inches of that and kept the bottom contours that are based on what Tom Wegener was doing with alaias. This board is only 16.5 inches wide, about 3/4 of an inch thick, and I used square rails. I used a morey boogie to get the rocker. I used that one only once and even though I had a lot of fun, I thought it was just a bit too narrow.
The last one has the funky colored bottom. This has the same rocker but it is about 20 inches wide, and maybe a little over an inch in the back half. I gave it a rolled entry and then square rails, with a totally flat bottom. I also cut the back like a sting to see if it would add a little bite when I’m on rail. I haven’t tried using it yet, I went back to riding my regular boards.
If I ever get around to making the little swim fins I’ll post it.
Nice work Sharkcountry, there so much you can learn from making your own boards, even if you only speculate as to why the design changes the performance, it’s a joy to ride your own craft.
For my latest fin design, I’ve had the CAD guy working on the drawings to get some prototypes made.
I’ve taken a leaf out of everyone’s design and added my own concepts.
ive taken a generous foot pocket from the DMC silicone swim fin because a cramped foot pocket is hell.
It’s got the flat blade top like an Mike Stewart Viper because it just makes sense to have a smooth flow across the blade without the foot pocket poking up.
It has the raised angled side strake of a DaFin but gonig fulllength like the LeBlon because the angled side create a firmer blade for thrust and also better hydrodynamics to keep the flow heading down the fin and not off to the sides.
My original idea is to distribute more of the blade area higher up on the fin and closer to the foot, thats where the power comes from in a kick. It means a quick, short kick will have more power like kicking a football rather than waiting for the water to get to the far end of the fin.
It’s obvoiusly not going to end there with plenty of prototypes coming. I’ve got a plan to make a single design that fits both feet, plenty of drainage, a robust heel strap, test different strake angles along the rails, always looking for the single goal of making it the most comfortable fin to wear and use.
I’ve been thinking about getting something like these training fins as an intermediate step to get my legs used to fins again, but I’m not sure. I’m concerned about the closed foot pocket versus an open heel type made for surfers. These Finis fins are interesting. My problem is that I surf places that break a good distance from the shore, and at low tides are too shallow to swim out.
Looking forward to seeing where all your work ends up.
Sharkcountry, I haven’t found a real difference between;the full foot pocket and the heel strap design. But the heel strap does use the sole to hold it in place.
Fins seem to fall into several categories,
there’s the very long bladed scuba fin…the shorter scuba fin like the UDT…the surf fin like Da Fin, Duck Feet…Then there’s the fun fin for snorkelling…and the very short blade training swim fin. See Pic.
A shorter or softer blade has less resistance so less drive. The stiffer blades have more effective drive but are harder to push.
The longer the blade the slower the cadence or stroke rate but you can still kick at the pace and force that suits you. I’d rather have an effective fin at any pace so I prefer Vipers, Da Fins, Duck Feet but each one isn’t perfect for me.
I think that the best fin for anyone is the one they like, so that’s why the advertising science exists. But its only when you try lots of fins that the science doesn’t matter, it’s how the fin performs.
Sharkcountry - thanks for the board photos and ride reports. It takes a while to work out the nuances of these boards and when conditions are most suited to them. Sometimes a paipo board is the best choice and sometimes it isn’t. I was sent photos of Barry’s paipo boards. Thanks for the tip off.
