Force Fins - what's the story?
Few other dive items trigger such heated debates on internet forums as Force Fins. They're either "hated" or "loved", it seems. Part of the controversy arrives from the number of different fin designs available (and to a much lesser degree two different materials), and the fact that (at least the more common type of Force Fin, the "Force Fin Pro") it requires/benefits from a different finning technique than most other fins. Simply fin using a faster, more streamlined approach to flutter kicks, and you will be moving ahead nicely. Still, having tried a few different models, there is more to it, and not every model is obviously perfect for any kind of diving. Here's our attempt to shed some light on them.
Force Fin Pro "facts" (probably subjective, but based on own experience):
Positives
- the short fin makes it easier to manouver in tight passages (wrecks, caves)
- much easier to walk and to climb ladders on boats, and they are less frequently stepped on by others on busy RIBs or other dive boats
- if you are prone to cramps, have knee or ankle problems, these fins can be your ticket to more relaxed diving or even extend your enjoyment of diving into later in life!
Cons:
- the design makes it harder to swim backwards, or to do helicopter turns on the spot - at least in the FF Pro model, the short ones - yes, you CAN do those manouvers, just not as easy as with Jetfins or the larger FF models such as the Extra or Excellerating.
- the Force Fin Pro design makes swimming with perfect horzontal trim slightly difficult, you easily appear much busier to other divers than those doing the "slow frog-kick and glide" with larger/stiffer fins (again, entirely possible with for example the Extra model)
- the FF Pro tend to kick up silt quite easily, as you do need to make many more small fin moves, and the resulting downward "flap" motion of them pushes water downwards quite effectively - this is obviously not always good (close to a silty bottom or wall in an Alp lake)
- don't even think to show up for GUE training in the regular short Pro model - they might be black, but far from DIR :-)
Strap Options
There are no buckles to break on a Force Fin. In the basic setup it includes a strap, which can be replaced with a Bungee Cord Set - consisting of a replacement washer, screw and plastic holder and the actual bungee cord. Others have successfully simply pulled a bungee cord through the two holes in the foot pocket. Be careful with this if you use the Tan Delta material though, as tight pulling on free-running bungee cord can cause heat, and the cord can go through your foot pocket... you've been warned.
Material choices - black Polyurethane or the mysterious "Tan Delta"?
"Tan Delta" is a special material offered by Force Fin in a variety of their models. Besides the fact it is expensive, it offers a higher "rebound" than the basic black Polyurethane material. What this means in real-life, is that the fins has more "snap" to it. When you fin, you will feel a tiny bit more resistance in some cases, but first and foremost more forward power.
Whether the Tan Delta material is any stronger (as in "longer-lasting"), is anyone's guess. The person I bought my Tan Delta Excellerating model from had a set of those where the fin literally broke off in front of the foot-pocket, he said. Needless to say, this set of fins was replaced by Force Fin without any questioning in a snap, as there was clearly some unusual manufacturing error. It is the replacement set I am currently using for my wetsuit adventures at the moment, in the Excellerating model, and it holds up perfectly. In fact, it even looks like new, especially when wet, which is what counts - it is quite gorgeous!
Another set of Force Fin Pro in Tan Delta we bought used from someone in California, had a cut in the material to the right of the foot pocket - probably caused by something sharp piercing through the material. It is only a cut about 1cm in length, and does not seem to "grow" or in any way impede function. Any other fin would probably have taken as much or more damage. The Tan Delta material is extremely strong, and the good thing is, it appears that even if you did get a cut in them (as we found in our used pair), this will not just continue to rip open any more. We successfully used a used pair of Red Ruby Tan Delta FF Pro's for several months without the little jack increasing in size at all.
All Force Fins, whether standard or Tan Delta material are extremely tough and can for example be left outside in the sun for seemingly indefinite periods of time. The shape does not change, the color may change a little over long periods of time (think 4-5 years), and of course they are bound to getting scratch marks. As soon as they are wet again, the Tan Delta's colors just jump right at you. Beautiful design for sure. But you have to pay for performance and design. But consider these fins are actually hand-made in America - not factory-pressed in China - a huge different in my mind as well. The same reason I purchased a backup torch from the original German manufacturer, and not a cheapo chinese copy.
Pro, Extra, Excellerating - what's with all the models?
The Pro is the basic shape, a short, highly manoeuvrable fin. You will hardly feel it is there, but it does move you forward very efficiently if you stick to short flutterkicks. It is not the best for frogkicking or heli turns, although with enough persistence and training, it can however be done.
The Extra is approximately the same "general shape" as the Pro, but in a longer, wider version. It can also have so-called Whiskers added, a pair of water channeling fins on top of the fin. Further, these can be turned so they are either level with the outside edge of the fin, giving least resistance or channeling power. Or, turn them inside towards eachother to truly get up your speed. This increases the water speed leaving your fin area, pushing you more strongly forward, but you will feel slightly more resistance or respectively, need more strength to fin, as well. Heli-turns, backward swimming - it is possible with these, without too much hassle. If you remove the "whiskers", they also have nothing that could ever really snag on a cave line or similar. Very robust, for serious gear hauling. A favourite of Kevin Gurr as seen in his excellent book "Technical Diving from the Bottom Up". I use this fin alternatively with Dive System's Tech (Jet) Fins for my drysuit diving.
The Excellerating model is similar to the Extra, but has a slimmer "body". It is a favourite of many tech divers, and offers an excellent ratio of power, low energy consumption and low overall weight. I use these fins in Tan Delta material for my wetsuit and holiday diving. They do really allow for effortless, fast swimming underwater - whether that is always a good thing, or a good way to dive, is another question. But if your buddy can keep up, and you want to do a bit of a sight-seeing tour underwater as opposed to cuddle up next to a nudibranch for 50 minutes, these are your underwater equivalent of the Audi R8 sportscar.
The following pictures illustrate the differences:
In Black - the Force Fin Extra, size: XXL in standard black material. In Blue - the Excellerating in Tan Delta (color: Sapphire Blue, size: XL), and finally in Red - the Pro model in Tan Delta (color: Ruby Red, size: XL).
Sure looks nice - Tan Delta in Sapphire Blue!
The adjustable whiskers - the difference is not massive, as even the wider position provides great thrust, but yes, you do feel a difference when narrowing them.
The Bob Evans signature, on every pair of Tan Delta material fins:
UPDATE: I've got hold of a set of early-model SD1 Military in Smoke Tan Delta material from Bob! First thing we did after having them shipped from sunny warm California? We took them Icediving in Austria...
UPDATE: Amazing deals to be had right now on ebay:
