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Post by SeaRat on Jan 13, 2006 17:56:58 GMT -8
Well, I got the modified fins in the water today. I may go back tomorrow. Thing is I really am not getting any measureable differences though I "feel" the splits are working better in the SkinDiver set. I tried to swim only a single lap and either this is not enough distance to reveal a speed difference or there is no difference. I swam such a short distance so as not to tire myself and introduce that as an error. Well, I guess I will need to swim a further distance to rule that out. A few tenths of a second are not statistically relevent to me and that is all I am getting--except with the NEW model UDTs purchased from our host Vintage Scuba, they are showing more speed by about 1.5 seconds. This is my first attempt, obviously I have underestimated the diffuculty of getting legitimate results. N Nemrod, Than is why I went to counting strokes a while back. I still have yet to enter the data from my swims two weeks ago. I'll see if I can do that over the weekend. One other way I have used is to get into the pool, start going down lane line, and close my eyes after establishing a good heading. This way, I'll see whether I start heading off in one direction or the other (right or left), depending upon which fin I'm using. I'll then switch the fin, and try again, and see whether it goes the other direction. Good luck, John
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mudhog
Regular Diver
Posts: 18
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Post by mudhog on Jan 14, 2006 12:40:00 GMT -8
I'm looking forward to your report on the Sea Wing fins, just today a pair showed up, size large, black, model #25-55-000. Just intime for the pool tomarrow. Didn't know about what looks like a one way vent feature till I got these in hand.
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Post by SeaRat on Jan 15, 2006 17:57:09 GMT -8
I had my Lightning Jet Fins, the Sea Wings, my UDT Duck Foot, and the Scoop Fin in the pool again today. No data, just swimming around.
The Sea Wing fins are actually pretty good. They are not as good as Jet Fins for the frog kick, but almost as good in regular flutter kicking. They are much lighter, and have less surface area than the Lightning Jet Fin, which by the way is a huge fin. They are probably much better than the regular (original) Jet Fin, which is smaller than my Lightning Jet Fin. I like them, and will be using them at times this coming season. They have a plastic blade, which lasts very well. The vents are the overlapping design, which close up a bit on the up stroke. They do "jet" the water too, as I checked with my hand when pushing water with the other hand.
Neither match up to my newer Scoop Fin design though.
SeaRat
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Post by kgehring on Jan 15, 2006 18:51:48 GMT -8
Have you tried testing with an u/w speedometer? There are a few floating around in the scuba community. There might be a chance that I can get my hads on one for a short while.
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Post by SeaRat on Jan 15, 2006 22:58:34 GMT -8
Karl,
That would be great, as I hope to do this kind of trial this summer. This is the same type of trial that the ScubaLabs did under Dr. James Grier's direction. I have a nice reservoir to do this in close by, so it would be very interesting to do.
John
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Post by nemrod on Jan 21, 2006 17:30:35 GMT -8
I went back to the pool yesterday and may go again tomorrow.
I am unable to determine any really useful info--that is my conclusion. I am swimming, ScubaPro Jet, split modified SkinDiver, SkinDiver, UDT, split UDT, Mares Power Plana, Force Fin Pro, USD Rocket.
What I think so far:
1)Based strictly on feel and lap times the Force Fins blow everything else away for speed. 2)Strongest acceleration from standing start, JetFin and UDT unmodified are very similar and both do modified/trick kicks about equal 3)Most tiring--UDT and Jet Fin 4)Favorite, this time around, the ol' SkinDivers, unmodified.
5)The splits in both the SkinDiver and the UDT modified versions do change the action of the fins, reducing acceleration and increasing top speed. The splits seem to make the fins easier to kick but again without being able to measure work I cannot say this is significant.
6)Timing laps proves nothing for efficiency because we cannot determine calories expended or O2 uptake to measure actual work.
7)The Power Planas were second fastest and very manuverable and seem to handle alternative kicks equal to the UDT and Jet 8) Force Fins s****k on the surface face down and they are the least manuverable overall--relying on fin imputs only to manuver 10)USD Rocket Fins are no good, at least as uncomfortable as the Jet and less powerfull. 11)Jet Fins kill my arches and hurt my legs 12)Full foot Power Planas and Force Fins were the most comfortable.
13)Scoops, well never got there yet, I notice Mares fins, Gull and several others have scoop like designs though not as prominant as are John's designs but since he wrote Mares long ago I suspect they did in fact use his design or at least there has been similar thinking at work here.
14) For a very old fins design the UDT owes no apologies, it is an entirely adequate scuba fin.
One other thing, I thought about counting kick cycles but since these fins all behave so differently and use differing kick types that too is useless to me. James
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Post by mossback on Jan 21, 2006 20:27:00 GMT -8
Searat and Nemrod
Been keeping up with y'all's experiments and just thought up a method of determing which fins produce the best over all performance.
Your both seem to be in pretty good shape so this method might provide some answers.
Establish a swim for a measured distance of 100 yards.
Only do one type of fin set per hour, and no more than 3 sets in a day. Try to maintain the same amount of time to swim for the 100 yards so you probably will want to experiment on that first to determine that time
.....the idea is to cover the distance in the same time span with the different fin types and determine how much effort your body makes to do that.
Before each start, check your pulse, record it and begain your swim. Do a normal cruise of your own style.
At the end of the 100 yards, recheck your pulse and record it.
The next day......or later when time permits, do the same routine but with a fast start and sustained speed. Checking and recording your pulse at the start and finish.
You could also note after each swim how you feel, breathing effort, note the tiredness or ache of your legs and or feet......etc...........
This might give you an idea of the amount of effort your body is having to exert over a given distance and given time which you can translate into fin efficency.
Someone feel free to enhance this method or shoot it down.................just a thought...........
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Post by SeaRat on Aug 8, 2016 17:28:07 GMT -8
I just had an inquiry on YouTube from one of the guys following my YouTube videos, asking about the fins I was using. I told him, I then referenced this thread. His reply was, So maybe someone else is interested in the scoop fin concept. Here's the YouTube video, which not only features my Scoop Fins, but also my USD Royal Aquamaster regulator: Speaking of that, I just received a pair of Farallon Fins with the leg support, to supplement some fin experiments I hope to do this fall. These are original Farallon Fins, and will help me out as mine are in bad shape, with cracked ribs and one cracked support. I got them from one of our own, Michael England. Thanks Michael. I'll post here on the experiments this fall. I think these are the fins: vintagescuba.proboards.com/thread/3155John
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