Scuba with freediving fins

[Eric Sedletzky]

But you used like 50x the energy you needed to. The idea when diving (sightseeing) is to conserve energy.

Yes the free dive fin pushes further, it requires a lot more energy. But what if you don't need to go far?

You don’t use 50+ times the energy even though it may seem like that because of the size of freediving fins. Freediving fins actually use way less energy to create the same amount of force as say Jet fins, that’s why freedivers use them. Freedivers need the most efficiency to power ratio and the long fin just happens to be the design that developed. If a scuba diver wants to go slow just barely move them and you go slow, but you do have the option to go fast if you want. A freediving fin can do everything a shorter scuba fin can do, but a shorter scuba fin can’t do everything a freediving fin can do.
The only exception is in a tight spot like in a wreck or cave.

 

[IncreaseMyT]

You don’t use 50+ times the energy even though it may seem like that because of the size of freediving fins. Freediving fins actually use way less energy to create the same amount of force as say Jet fins, that’s why freedivers use them. Freedivers need the most efficiency to power ratio and the long fin just happens to be the design that developed. If a scuba diver wants to go slow just barely move them and you go slow, but you do have the option to go fast if you want. A freediving fin can do everything a shorter scuba fin can do, but a shorter scuba fin can’t do everything a freediving fin can do.
The only exception is in a tight spot like in a wreck or cave.

I was talking about using a sledge hammer instead of a 25 ounce hammer. It takes a lot more force to lift and then swing the sledge hammer. Its not proportionate to the weight difference either because of the increased leverage due to the longer handle.

What your saying is simply not true, free diving fins, because of their length and usual stiffness, take a lot more force to kick than a shorter more flexible fin, even just shorter and less flexible. This is a fact.

I understand why free divers use those type of fins, I free dive a lot myself. But the piece of the puzzle your not calculating is that free div fins are designed to propel the diver long distances efficiently. If you don't need the travel, then you will use more energy kicking the free diving fin. This isn't really debatable, its simple physics.

This will be my last post in this thread, because people just keep repeating the same false information and swearing its true.

 

[ronscuba]

Stiff plastic blade vs. soft fiberglass blade.


Not all fins are the same. Soft fiberglass blade is easy to kick and you can get travel just using your ankles. The stiff side tendons on the foot pocket provide the power when needed and only come into play when you kick harder and wider.

In this video you can see how the fiberglass blade is more reactive, more flexible, but the foot pocket is stiff. Fiberglass fins by Mako and Leaderfins are under $180.

I hope this video shows that free dive fins do not have to be stiff and hard to kick. If you want to travel small distances, flick your ankles a few times. It uses minimal energy and you travel further than a frog kick. When you want or need to move fast, travel far or dive in current, it is nice to have the power of a free dive fin on your feet.

 

[drbill]

Two instructors out here on Catalina have used them exclusively. Personally I see no benefit for me because I tend to go slow and stop to film critters. I rarely have to travel long distances or at any speed.

 

[andy2667]

Well I guess you sure could use them in that manner but thats not what they are intended for and they def wouldn't be that efficient. I am unsure why everyone is fighting this so hard its common sense.

Basically you are trying to convince me that I should just have one speargun, a huge 60 inch sub and just use that the whole time. Just shoot snapper with it?

Or would it be more beneficial to have a smaller gun for smaller fish?

Its the same thing with fins, your trying to use a sledge hammer on a roofing nail. Can it be done? Certainly, is it overkill? Absolutely.

Not sure if you have used long free diving fins before. If not, I recommend you to try it and experience it for more real life experience comments.

I have used a few fins before including Seawing Nova, Mares (a few models), Gull full foot and open heel rubber fins which are short and powerful....but now uses mostly long free diving fins.

For me, long fins will not kick up mud even doing sandy bottom mud diving. How come proper frog kicks (or flutter kicks with foot raised up) will kick up mud/sand? In my experience, long fins can do slow relaxed swimming but in a more efficient manner. To me, long free diving fins is more efficient whatever speed or kicks I am using. This resulted in using less air for my situation and techniques. The only down side of the long freediving fins is that they are not suitable for diving where space very limited and may cause a bit trouble when putting them on in a boat congested with divers.

FYI, quite a lot of DMs in Maldives are now using long free diving fins.

You may have your own opinion or experience but I recommend you to try them properly before making a decision of proper comment.

 

[IncreaseMyT]

Have used them many times. Some dives they work great. Some dives they are super overkill.

 

[Soloist]

It really boils down to personal preference and simply stated I would use freediving fins all the time if possible. Unfortunately it’s not practical. As stated before traveling with longs fins and swimming thru confined spaces can be problematic. Shore diving on rocky terrain is a major PITA for any “full foot” fin. Not sure I comprehend the overkill and effort argument. If I am NOT fighting against the current or in a need for speed, no problem. My car has a 330HP V6 engine, but I still maintain a speed of 15 mph thru the neighborhood....

 

[IncreaseMyT]

Yea and it uses more gas than a 4 cylinder

 

[IncreaseMyT]

I know lots of people that only have free dive fins, and they use them well. I also know people that don’t have have any free dive fins.

If your doing a dive and stopping and turning a lot, and the goal of the dive is to stay down as long as possible and you are staying in a relatively small area, a free dive fin is not optimal. You can definitely use then but a short stiff fin, like a jet fin, would be better. A lot of people who river dive use a short stiff fin.

So it just depends on the dive IMHO.

You can see in this video both the DM and the guy I got paired with had fr e dive fins. The DM knew how to use them, the buddy did not and he was all over the place and his fins hit the wreck more times than I can count:


That’s a big wreck and of you are good with free dive fins it’s afvantagous, if your not you’ll end up looking like my buddy

 

[johndiver999]

I know lots of people that only have free dive fins, and they use them well. I also know people that don’t have have any free dive fins.

If your doing a dive and stopping and turning a lot, and the goal of the dive is to stay down as long as possible and you are staying in a relatively small area, a free dive fin is not optimal. You can definitely use then but a short stiff fin, like a jet fin, would be better. A lot of people who river dive use a short stiff fin.

So it just depends on the dive IMHO.

You can see in this video both the DM and the guy I got paired with had fr e dive fins. The DM knew how to use them, the buddy did not and he was all over the place and his fins hit the wreck more times than I can count:


That’s a big wreck and of you are good with free dive fins it’s afvantagous, if your not you’ll end up looking like my buddy

I looked at the start of the video. The leader, who I assume is a dive master is not using "long fins". Those are not considered freedive fins. The buddy, the second guy is using a relatively sloppy kick technique. It is not terrible, but not the best.

A freedive fin does not consume energy unless it is being kicked. If a diver is moving slowly or stationary, then the longfin does not waste energy or air. Your analogy of a 8-cylinder car is off the mark, because an internal combustion engine turns heat into motion, and a larger engine will waste more heat at idle than a small engine - really not analogous to a swim fin.

I'm not sure the video is effective in furthering your "poor efficiency" position.