Scuba with freediving fins

[stuartv]

It is true. Your premise involves covering distance, if you don't need to do that, the lesser resistance on a shorter fin will cause you to expend less energy. I thought this was common knowledge.

It's not common knowledge because it is wrong.

If you go 100 feet and use less energy using freedive fins, then you will also use less energy to go 1 foot.

 

[АлександрД]

..My intention is to use free diving fins for current dives. During my last two trips to Raja Ampat and Socoro, on some dives with strong currents, I was not able to move with my Mares Quadro+ fins, while three other divers who were using free diving fins moved through the current without any problem.

From the discussion, it appears that fiberglass blades are a good choice for scuba diving.

I`m used long fins (Cressi Gara 3000 LD) for diving for some years. It was very nice. Once we had going around small island (rock) and on the corner met frontal current, very strong.
(here. right side)
My two buddies (experienced, I was just newbe in those times) trying to catching rocks, stay near the wall, and slowly climbing forward (we have to pass around 10 m, to turn behind the corner). I`m with long fins easily swimmed nearby in the water. I was able to going against current without big forces.
Before they looking for me as on jerk, who used long fins just for kidding or other case. Later they start to look on it with much greater
respect
P.S. later we have jet flight between two rocks on the narrow canyon

Our way against current was fully compensated by this flight

 

[andy2667]

It is true. Your premise involves covering distance, if you don't need to do that, the lesser resistance on a shorter fin will cause you to expend less energy. I thought this was common knowledge.

Agree that different fins has different applications. For example, it is not practical using free diving fins for wreck penetration or cave diving. For these applications, better use jet fins, Mares Quattro or other fins alike. For mud diving with no current and not requiring covering distance, the short fins are less troublesome.

However, for most of the recreational diving situation in particular in handling current, covering distance or saving energy or crusing the reef, free diving fins are the way to go.

Not discussing physics or fluid mechanics as it is far more complicated to explain though I am a mechanical engineer by training, just want to share my real life experience.

I used to use Mares Quadro (have considered between the Jet and the Quadro and finally chose the quadro because it may be better for flutter kick). In a Maldive Liveaboard trip when I was handling current, finning my Quadro crazily, I hardly moved a few meters to get on the rock for anchoring. After that, I started evaluating my trusted Quadro fins and searched for fins more suitable for handling current. Then ....the long free divining fins came to my mind. Initially, I was curious if I could handle this type of fins and concerned about if it need extra efforts for using it. Finally, I gave it a try.

On boy! The long free diving fins are so much more powerful and so much more efficient compared with my Mares Quadro. Also, they handle all sort of kicking well. Flutter kick, frog kick, helicopter finning, backward kick, scissor kick.....etc, they handle as good as my Mares Quadro if not better. Even frog kicks are much more powerful. The only difference is that they are longer and is not suitable for diving in places where space is limited such as wreck, cave...etc.

For handling current, no contest. They are so much more powerful. When other divers using short scuba fins finning like crazy moving against current, I just do normal finning and could follow closely to the DM who has been finning crazily against current using normal scuba fins. In term of efficiency, they are a lot better, For reef crusing without strong current, you can use leisure frog kick (which I think is not a very efficient type of kick for propulsion), or even better, very small flutter kick. Just move your ankle using very small amplitude flutter kick and you get good propulsion with very little effort. These are my real life experience. No need for long long debate in physics/fluid mechanics....etc. I now use much less air compared with the dates when I was using Mares Quadro under similar conditions.

Of course, if the trimming is not proper the finning techniques are wrong, the results may be very different. For an improper trimmed diver inclined 45 deg at the propulsion direction, the longer fins may result in larger cross section area against the flow meaning more drags. Improper flutter kicks such as bicycle type finning may not see the benefit of long fins.

For materials, I still think plastic long fins with the appropriate stiffness is more appropriate than fibre glass or carbon fins for scuba diving. The difference in efficiency may be minimal but plastic fins are a lot cheaper and far more durable when you consider how the crews handle your fins.

 

[MAKO Spearguns]

This is the exact kind of feedback we hear constantly from scuba customers who start using longfins. Efficiency and power when you need it.

The comment about using tiny little, rapid flutter kicks for gentle cruising is spot on as well. The tiny little kicks use very little energy and are just strong enough to get the long blades into an S-shape which allows the diver to benefit from the elasticity and recovery of the blade.

 

[dmaziuk]

This is the exact kind of feedback we hear constantly from scuba customers who start using longfins. Efficiency and power when you need it.

So... any plans to make open-heel pockets for us ironshore walkers? Immersions are the only ones I know of and their shipping cost plus my hobbit feet (50% chance I'll need to send them back for the other size) make force fins seem inexpensive.

 

[deeno]

Ditto on open heel! JBL and hammerhead also have open heel removable pockets, but I'm not sure if those other branded ones will fit a hardsoled shoe

 

[Laval]

Agree that different fins has different applications. For example, it is not practical using free diving fins for wreck penetration or cave diving. For these applications, better use jet fins, Mares Quattro or other fins alike. For mud diving with no current and not requiring covering distance, the short fins are less troublesome.

However, for most of the recreational diving situation in particular in handling current, covering distance or saving energy or crusing the reef, free diving fins are the way to go.

Not discussing physics or fluid mechanics as it is far more complicated to explain though I am a mechanical engineer by training, just want to share my real life experience.

I used to use Mares Quadro (have considered between the Jet and the Quadro and finally chose the quadro because it may be better for flutter kick). In a Maldive Liveaboard trip when I was handling current, finning my Quadro crazily, I hardly moved a few meters to get on the rock for anchoring. After that, I started evaluating my trusted Quadro fins and searched for fins more suitable for handling current. Then ....the long free divining fins came to my mind. Initially, I was curious if I could handle this type of fins and concerned about if it need extra efforts for using it. Finally, I gave it a try.

On boy! The long free diving fins are so much more powerful and so much more efficient compared with my Mares Quadro. Also, they handle all sort of kicking well. Flutter kick, frog kick, helicopter finning, backward kick, scissor kick.....etc, they handle as good as my Mares Quadro if not better. Even frog kicks are much more powerful. The only difference is that they are longer and is not suitable for diving in places where space is limited such as wreck, cave...etc.

For handling current, no contest. They are so much more powerful. When other divers using short scuba fins finning like crazy moving against current, I just do normal finning and could follow closely to the DM who has been finning crazily against current using normal scuba fins. In term of efficiency, they are a lot better, For reef crusing without strong current, you can use leisure frog kick (which I think is not a very efficient type of kick for propulsion), or even better, very small flutter kick. Just move your ankle using very small amplitude flutter kick and you get good propulsion with very little effort. These are my real life experience. No need for long long debate in physics/fluid mechanics....etc. I now use much less air compared with the dates when I was using Mares Quadro under similar conditions.

Of course, if the trimming is not proper the finning techniques are wrong, the results may be very different. For an improper trimmed diver inclined 45 deg at the propulsion direction, the longer fins may result in larger cross section area against the flow meaning more drags. Improper flutter kicks such as bicycle type finning may not see the benefit of long fins.

For materials, I still think plastic long fins with the appropriate stiffness is more appropriate than fibre glass or carbon fins for scuba diving. The difference in efficiency may be minimal but plastic fins are a lot cheaper and far more durable when you consider how the crews handle your fins.

Hey andy2667,
Thank you very much for your detailed feedback. I appreciated it very much.

 

[IncreaseMyT]

Yea but its not just cave and wreck and then always long fins is all I am saying. It depends on what you are doing. Lets say your shooting a video or wanting to get some pics of the reef, your going to be moving really slow, not covering a large area on the dive. So no you wouldn't want to use free dive fins. You may also be getting close ups of fish on the reef and long fins would be dragging. Thats just one example off the top of my head, there are a bunch.

Conversely yes there a bunch of examples of when you want to use free dive fins, but my main two points were simply:

1: You will want both

2: Free dive fins are not always more efficient. If you don't need to cover distance on a dive shorter fins will be far less exhausting.

 

[EireDiver606]

Wouldn’t recommend the freediving fins for cold water diving due to the full foot pocket.

 

[MAKO Spearguns]

Yea but its not just cave and wreck and then always long fins is all I am saying. It depends on what you are doing. Lets say your shooting a video or wanting to get some pics of the reef, your going to be moving really slow, not covering a large area on the dive. So no you wouldn't want to use free dive fins. You may also be getting close ups of fish on the reef and long fins would be dragging. Thats just one example off the top of my head, there are a bunch.

Conversely yes there a bunch of examples of when you want to use free dive fins, but my main two points were simply:

1: You will want both

2: Free dive fins are not always more efficient. If you don't need to cover distance on a dive shorter fins will be far less exhausting.

I am unsure why the idea that long fins (freedive fins) can be used in a very relaxed and gentle manner is difficult to convey. Freedivers often move extremely slowly and smoothly when stalking a fish.

Also, the idea of longfins "dragging" on the bottom is something that is completely avoidable if the diver has sufficient situational awareness and uses good technique. If the diver needs to swim very close to a silty or delicate bottom, a skilled diver can use an alternate form of kicking which places the knees at an angle of approximately 90 degrees and then kick with the ankles with a short amplitude kick. This can be done in longfins and as well as typical scuba fins.

It is probably not the most efficient kick pattern to use, but it is effective for this special condition.

I don't think it is unusual for some videographers to select the longer "freedive" type of fins.

As for the questions about an open-heel freedive fin pocket. We have considered it in the past, but the costs for a footpocket mold for each foot size is a considerable investment, more than something we can pursue at this time. An open heel freedive fin will accommodate a larger dive boot and one with a sole, but the trade off is that the footpocket is slightly less stable and this is generally believed to result in the loss of energy and efficiency of the kick. It also necessitates the use of a buckle assembly and strap which represent an increase in drag and also a potential location to catch lines or kelp etc.

The standard full foot fin, provides no structures to allow a line to be caught or trapped on the heel- a very important consideration to a freedive hunter that is ascending on one breath and dealing with fish that may be tethered by a kevlar line. Thus, it is not a compromise that most freedivers are willing to make. Possibly something to be considered by scuba divers as well?

In short, long open heel freedive fins may work well for some people that absolutely must use a hard sole boot immediately before entering the water (and immediately afterward).

I very much appreciate the feedback and suggestions, but we don't see a sufficient market for an open heel footpocket, especially when some competitors already are providing that option.

Another issue that has been raised in this thread is coldwater diving. A full foot fin can definitely be used in coldwater, the diver just needs to select the appropriate neoprene dive socks to be worn under the fin. Getting the fins off and on while wearing very heavy gloves may be more challenging without the presence of an easily operated buckle etc. so this is another trade off that a diver needs to consider.