Not exactly sure, I know they went into the late 60s because I remember them in stores along with the other favorite of mine, the Voit SkinDiver. Sure wish for an updated version of this fin, a little bigger and a little stiffer would be fantastic. Unlike the UDT which are great fins the full foot Vikings were actually comfortable. To keep from rubbing blisters I need thin fin socks with my UDTs and I can use my Vikings and SkinDivers barefooted. I sold a pair not long ago for 110 dollars. The Viking A66 is larger than the A6. I never realized there were different models but it was the A66 that I used to use along with the SkinDivers which are more like the A6. James
I bought some of the A66 in an "Extralarge" version, which was the only fins one of my PJ buddies could fit. Don was 6' 11" tall, and wore a size 14 or 16, and these were the only fins he could wear that were out at the time (1970). So I know they were made at least into 1970. I had a pair which I modified to my "scoop" fin version, and they were really nice that way (a combination full-foot Viking with the advantages of a Mares _____ (I'll remember it and fill this in later) fin, actually better as the scoop was better). I'll get a photo of that pair, which I used in fin experiments in early 1970.
Post by Broxton Carol on Nov 11, 2005 8:41:20 GMT -8
I had a pair of those CHURCHILL TYPE voit fins in 1956. I was a doumb kid who used them so much they cut into my feet on the tops. They were a medium green color. I think I got them at them from the Western Auto store on the miracle mile! I saw a movie on tv last night called "DEEP WATER" on the FOX movie network. Talk about rare gear. How about 4 divers with TRIPLES and BROXTONS swimming along getting into knife fights!! Just unreal!! Almost like the vintage dive at WAZEE!
Post by DavidRitchieWilson on Nov 12, 2005 3:14:29 GMT -8
The earliest reference I can find in my own diving library to Voit Viking fins is my Carrier & Carrier 1955 edition of "Dive" with its wonderful treasure-trove "Equipment Listing" appendix. Page 265 has under "Aqua Gun Co.":
A-6 Viking two-tone blue foot pocket, big blade, med. 7-9, med-lg. 9-11, lg. 11-14. $12.95.
I can also confirm that one version of the Vikings did indeed have an asymmetrical blade, like the original Churchills. W. G. Fisher's "Comparative Evaluation of Swim Fins" (Evaluation Report 18-57), Washington: Naval Experimental Unit, 1 March 1957, has a photograph of these fins.
I bought a pair of Voit Vikings recently on Ebay and tried them out during one of my North Sea snorkelling forays. I agree they are very comfortable, although the blades were stiffer than I was expecting. This confirms the judgement in my copy of an article entiled "Underwater swimming equipment" in "Consumer Reports", Vol. 22, Part 7, of July 1957 (pages 324-330) that Vikings belong to a group of fins that "would probably be more suitable for strong swimmers - less so generally for women, children and novices". The article goes on to describe Vikings as follows:
VIKING Cat. No. A6 (W. J. Voit Rubber Corp), $10.95. Non-ajustable fin with "full foot" and closed toe. Fin angled downward. No anti-skid pattern. The large-size fin of this make floated; the medium-size fin did not.
Interesting that the price of the fins had gone down $2 between 1955 and 1957!
Post by DavidRitchieWilson on Nov 12, 2005 4:14:11 GMT -8
A short postscript to my previous answer. I've had another look at the two editions of the Carrier & Carrier "Dive" I own (1955 and 1963). The earlier edition has a drawing (page 108) of a Voit Viking fin with a heelpiece that is cut away on the sides, but not at the back, rather like a sandal. The 1963 edition has a photograph (p. 261) of a non-adjustable open-heel version of a Voit Viking. I had always assumed that Voit Vikings were only ever available in a full-foot version.
I don't recall a Voit Viking fin with this kind of cutout (open on the sides of the fins). I think it is significant that the Carriers only had a drawing, and not a photo, of this. Perhaps they were reproducing a prototype in the drawing. I do remember the actual A66 fins that I bought had a dotted line molded into the foot pocket, and the full-foot heel portion could be cut away to make it into a molded strap design. The strap portion of the molded heel was much thicker than the heel portion.
They were available with the cutout heel. It was not common but body surfers have always prefered that type I think. I will have to look but I think I have a 63 SD with an advertisment for Viking fins describing that type. James
Thanks for the great discussion so far. I had a pair of Vikings in the mid-70s, but I'm not too sure they weren't hand-me-downs. I vaguely recall buying them myself for a Hawaii trip with my paper route money, but you know how memory starts playing tricks on you decades later! This is part of the reason I originally asked the question. So far, it has been confirmed to 1970 in this thread.
Silly humans, fins are for fish. Mammals use flippers.
Years ago, I experimented with fin blade designs, and I still dive what I now call my "scoop fin" modification. My experiments were on Voit Viking A66 fins. I replaced the whole fin blade with a flexible interior, and tried to patent it. This was not to be, as there was an existing patent which covered the concept (Frank N. Murdock, Bellevue, Washington, Patent #3,411,165). But I made the effort, and put together the data to prove my point that this blade design is better than anything currently (still, today) on the market. I did this research starting in 1968, using USD Caravelle fins (with the removable blade). But in 1970, I found the Voit Viking A66 fins, and modifide those. They proved to be better (larger surface area) than the USD Caravelle fins. Here's a photo of them being used in Alexander Springs State Park, Florida (I was stationed at McCoy AFB, in Orlando, at the time):
Photo Copyright 2005, John C. Ratliff If you'll look at the Viking fin's foot pocket, you will see that the full-foot part has been cut out. I did that along the dotted line that was on the foot pocket, as it is much easier to hold strap fins that full-foot fins. This is the option I was discussing above.
When I applied for a patent and conducted a patent search, I put together this analysis of force vectors, based on the analysis that Fred Roberts had also done in his book, Basic Scuba. Here's the diagram of that analysis:
Note the way the strings lay right down the fin blade, proving that the water streams out behind the fin rather than rolling off the side (as does water on a flat blade). This is more effective than the split blade concept, as none of the propulsive force is lost by the water going through the blade. 'Just an interesting aside on another better, but unsuccessful, diving concept. My disclosure statement was dated July 1, 1971. I went to Vietnam that October, and pursued it further from there, and actually right up to the present. Anyone interested?
What! You DESTROYED a pair of Voit Vikings! Just kidding ;D I have only seen A6s and a pair of the Churchill style. I have yet to see a pair of A66s. Very interesting design concept. Seems to make sense. But what absolutely and truly amazes me is how you were able to locate that old paperwork and the corresponding photograph from way back when! You must be the most organized person I know. I'd love to see your filing system. Thanks for sharing the information and photograghs. Innovation can be fun.
Silly humans, fins are for fish. Mammals use flippers.
Thanks for sharing the information and photographs.
Nice work. I like your graphical analysis, nice free-body diagrams (nice sketches). That is a great picture of the fins with the streamers.
It seems to be a great idea. But, I am afraid the same (or similar) concept is been used on at least one of the modern fins. I believe the SeaQuest Thruster fins have a soft center design to work in a similar fashion. It looks like your prototype may work more effectively than SeaQuest production fins, but in principle at least they do seem to be design with a similar concept in mind.
I am still impressed with your design and prototype fabrication and testing over 35 years ago. Your prototype fins looked great, in particular if they are a homemade prototype (but even for a professional shop). And like duckbill, I am very impressed with your filing system.
I have to ask, were you doing this just as a hobby?
Yes, this was a hobby. I got my degree in zoology, and in my senior year of college was told there were no jobs, so I got a second degree in health. 'Should have gone for engineering (my son is a mechanical engineer). But I studied fish caudal fins, and came to the realization that they mostly worked on two principals. For fish that were fairly slow movers, they used a design which incorporated a flexible interior and fairly stiff exterior. Fish have a more refined system, in that with the caudal fin has rays which can be controlled individually by muscular action in the peduncle of the fin.
This allows all sorts of actions we cannot do. But the basic principal can be applied to swim fins.
The other type of fin is basically a hydroplane in fish such as tuna; these are not practical for divers, as these fins need a kick frequency that is too high for humans to reproduce. Here is a site about a robotic tuna that MIT is working on which shows the caudal fin type:
If you look at either the Plana Avanti or the Thruster, you will see that they do not have enough "bow" in the middle to be the equivalent of the Scoop Fin that I produced. The trailing edge of the Scoop Fin should be almost a semicircle, instead of a flat surface. The Plana Avanti is not deeply bowed enough to give maximum advantage. Here's a new Avanti:
Mares knows about this, as I wrote them some years ago with these concepts. I have a number of Mares fins (Avanti), which I have modified and continue to dive. I will get a photo of my current fins here sometime.
I have used these fins for all my diving since 1971. I have made parascuba jumps with them (they are better in a HC-130 airstream than other fins, as the wind doesn't catch them as much when standing in the door), and dived them seemingly forever now. My frustration is that I cannot even give the design away (perhaps because of the Murdock patent), and nobody will produce them. So I still make my own. The biggest problem I had to get over was actually cutting a perfectly good pair of fins up to make the modifications.
They have one other advantage over current fins, in that they have very little splash. When I made the first modifications, in Okinawa with the USD Caravelle fins, I tested them out against fins of the time in a pool, and in open water dives and swims. In Florida, I remember being in a lake, and using the modified Vikings, and being able to displace aquatic plants and algea about twenty feet below the surface while stroking upright on the surface with just a stroke or two.
I now have other concepts which are even more advanced, and hope to use them to revolutionize underwater swimming at some point (when I get the time--it is still a hobby). It will be the difference in underwater swimming that bicycling is to running.
Very clever designs, I hope you eventually are successful with a patent.
I think that to some extent modern split fins like Apollo and ScubaPro Split which are rubber with fairly stiff side rails and flexible center planes provide action similar to your scoop fin. Notice when you see them in action the fins flex considerably which would provide a much more rearward force vector than my favorite stiff as a board UDTs. Also, everyone's favorite fin, the Force Fin, does the same thing. All I can say about Force Fins is that they require no effort and when ever I use them I find myself passing dolphins---well--not really but there is something to them. I have not decided whether there is a lift component to fin action or if it is mostly water displacement. Your scoop design is certainly a water displacement design. An airplane wing or rocket engine displaces air/gas downward and when the velocity/mass deflected downward/rearward exceeds the weight of the machine it has positive lift. Not exactly per Bernouli which seeks a vacum above a lifting surface which alone cannot account for the total lift (of a wing) required so I suppose both principles work together. I think the Force Fin and split fins are very effective at displacing large volumes of water for a given effort. These split designs and the FF seem to work best with high beat flutter kicks. Now, sure, I know the Frog kick is the current darling but I used to be a swimmer and way back also swam long distance open water competitions as well and anyone thinks that a frog kick is more effective than a flutter I welcome them to a few laps in the pool (not really--I am old and slow). I ain't never seen a frog kick being used three miles into an open water race. That is likely because everyone using the flutter kick would be about 2.6 miles ahead of the frog kicker--lol. As you know swimmer often shave before competition events, now some of that is to reduce drag supposedly but the main reason is that it makes the skin very sensitive and increases the swimmers "feel" for the water. A swimmer can feel the pressure changes from his arm and leg movement and "catch" the pressure pulses as they roll along the body, created first by the arms and hands and then continued with the leg/feet. Not a very good description--sorry--but it is something like that. I doubt divers will ever have that level of propulsion discipline though some competitive skindivers may. Anyways, I think there is certainly room for improvement on fin design. I wish Apollo would make their split fin without the split, just a thin flex groove where the current split is located. Good luck.
I have tested the Force Fin in the 1980s, and agree that it works quite well, but only on the down kick. Force Fins are more along the "tuna" design, and need a high frequency and force to be effective (see above). I got into a dispute with Bob Evans when I was Finswimming Director for the Underwater Society of America in the 1980s, when I published a design to make monofins more comfortable by extending the foot pocket's bottom to the heel (the monofins of the time were using a "duckfeet" type of open heel design, and were putting a lot of pressure on the toes (due to their extended length of flat fiberglass). Mr. Evans thought I was describing a concept that was covered by his patent, when in reality I was describing what was the then-common style used in many commercial diving fins, but not yet in the monofin. He at one point was going to produce a monofin, but apparently decided not to get into it. Here is a link to his website:
The split fin design also is very close, but as I described above, allows water to be lost through the fin's center. Because water is pretty viscous, not all of that is lost to forward propulsion, but I have pretty well satisfied myself that the flexible membrane of the Scoop Fin is better. You do see fish swimming around quite successfully with mangled fins, and this is what I consider the split fin to be, an mangled fin ;D
Duckbill, getting back to the Voit Viking A66 fins, take a look at the length of the blade in the photo above. I think it is at least 6 inches longer than the corresponding A6 blade.
PS--I added a link to an MIT site which discusses a robotic tuna as a swimming concept in the above post.