Five pair of freediving fins. Cressi, Omer, Mares Razor Carbon, C4, UP-F1

Left to right: Cressi Gara 2000, Omer Tuna Comp, Mares Razor Carbon, C4 Carbon, Omer UP-F1 Carbon

I’ve been freediving for quite some time and have used several different pairs of fins over the years.  After years of diving plastic blade fins, I finally made the decision to move to carbon fiber.  I debated long and hard, looked at, and tested several brands (Mares Razor Carbon, Omer UP-F1, C4) before I actually pulled the trigger on my first pair of carbon fiber fins.  Constant weight, and dynamic are my favorite two categories of freediving, and most of my training is in New England, where the temperature of the water requires a 7mm wetsuit pretty much year round.  I wear 14 pounds of lead to compensate for the buoyancy of the the suit (buoyant at 5 meters with empty lungs, neutral at 10m with full lungs),  which means at 30 to 40 meters when the suit is compressed, that 14 pounds makes you work really hard on the way back up.  Thus, a powerful and efficient pair of fins is critical to my favorite forms of diving.

Omer tuna competition freediving fins

Omer Tuna Comp fins

A little History:

The Cressi Gara 2000 fins were my first freediving fins, and they have a very flexible blue plastic blade.  The first time I dove them to 30+ meters I remember the sensation of starting my kick for the surface, and not really getting any significant upward motion until the third kick cycle.  I immediately went out and ordered the stiffest fins I could find on the market at the time, and ended up with the Omer Tuna Competition fins.

Carbon fiber fins were a brand new technology at the time, very expensive, and notoriously fragile, so I opted for plastic blades for a bit longer.  After receiving the Omer Tuna Comp. fins I got right in the water to test them on some deep dives.  Diving 30+ meters with those was a totally different experience than with the Cressi fins.  One kick cycle was enough to get moving back to the surface, and I dove those almost exclusively for the next 10+ years.

Fast Forward to 2016:

In February 2016 after a prolonged hiatus, I started freedive training regularly again with East Coast Divers’ Nick Fazah.  I was perfectly happy to dust off my old faithful Omer Tuna Comps, but they were beginning to show their age.  Small cracks in the rubber of one of the footpockets after close to 15 years of service made me begin to think it was time to get a new pair of fins.

Much has changed in fin technology in the last 15 years.  Carbon fiber construction has become much less fragile, and a lot of thought and engineering has been put into the variable flexibility along the length of the fin blade.  The first things you will notice about carbon fiber fins is that they are noticeably lighter, and considerably more flexible than plastic blade fins.  I was used to very stiff plastic blades, so my primary concern when switching to carbon fiber was whether I would get the same power from them at depth.

One thing to note is that some freedivers will mix and match blades and foot pockets.  Many people find the Mares foot pockets fit them well, and will find then install the blades that suit them best.  That is definitely a valid approach to finding your perfect set of fins.  Get that perfect comfortable fit with the foot pocket, then select the blades you like.  In the tests I conducted for this article I stayed with the stock blades that were issued with each brand of fins.

Pool Tests:

BU training poolMy first step toward picking a new pair of fins was to read about what carbon fins other people were diving on forums.  My second step was to gather as many of the different kinds I could get my hands on to test at the pool.  I brought a collection of five different fins.  Cressi Gara 2000 (soft plastic blade), Omer Tuna Competition (stiff plastic blade), Mares Razor Carbon (carbon fiber), C4 (carbon fiber), and Omer UP-F1 (carbon fiber).

The pool tests would establish a feel for the efficiency and relative power of the different fins, and arrive at a fin that sits at the crossroad of performance and affordability.

My test criteria

  • Count kick cycles across a 25 yard length of pool at an easy relaxed (medium slow) pace.
  • Time a 25 yard sprint  at full speed.

Omer Tuna Competition Test:

I got in the water with my Omer Tuna Competition fins to warm up and also set a baseline of what I was used to.  After a few laps I counted my kick cycles for a couple of splits.  On a medium slow pace with medium amplitude kicks I did a few 25 yard 9 kick cycle splits.  I eventually got it down to just under 9 cycles with those fins.

Cressi Gara 2000 Test:

Just for fun, I switched to the Cressi Gara 2000 fins.  As these are a super soft plastic blade I did not expect them to bring any surprises to the table.  They were added to the test as a reference of how wide a progression of fin performance one could pick from.  The best performance for those were 9 cycles.

The foot pockets are super comfortable and very similar to the Mares foot pocket design.  These are good first time entry level fins, not very expensive, easy to kick, and will take a beating on the rocks without breaking.

Mares Razor Carbon Test:

Mares Razor Carbon fiber freediving fins by the poolI cleansed my palate by doing a couple more laps with the Omer Tuna Comps to get back to my baseline, and then tried on the Mares Razor Carbons.  As soon as I slid into the water I could feel the difference.  The flexibility of the blade offered a drastic reduction of the torque on my ankles.  They felt light and fluid with my kick, whereas the Omer Tuna Comps feel like planks strapped to your feet.

I had to swim around a bit, and watch the flex and snap of the blade to see what it was actually doing, but then I got down to business.  I did about four to five 25 yard splits, and averaged around 8 1/2 kick cycles on the first couple lengths, and then dropped down to 8 cycles on the last few.

This was an obvious improvement in efficiency and thrust with a considerable reduction on effort over the plastic blade fins.  My first thought was that carbon fins would be great for anyone who wants to dive without putting a ton of stress on their joints.  The second thought was that my fears about the flexibility of the carbon blades not having the power I required were quickly melting away.  Same distance same speed, less effort.  This was a definite selling point for me.  If I am using less effort/energy to travel the same distance and speed then I am using my oxygen more efficiently, which will mean longer distances in dynamic dives.

These also performed the best out of all the fins on the sprint test, which I go into more detail below.

C4 Test:

Next up were the C4’s.  After resetting my baseline again I strapped on the C4’s and did a few laps with them.  These performed pretty much on par with the feel and power of the Mares Razor Carbons with 8 to 8 1/2 kick cycles per 25 yard split.  The real difference these fins seem to have is a more custom style foot pocket that you can actually lace up to get a super snug fit if you are an in between size.  This may be a good offering for some people who just can’t find the right foot pocket in a pair of fins, but not something that made much of a difference for me.  The only other difference I noticed was that they seemed to be a bit heavier than the other fins, probably due to the way the foot pocket is fastened to the blade.

One not so great feature of the C4’s is that the side rails on the blade detach fairly easily after some time of use, and I have heard complaints from owners of having to glue the rails back on every night after diving.

Omer UP-F1 Test:

different views of the Omer UP-F1 freediving fin

Different views of the Omer UP-F1 freediving fin

I have to admit I was very curious to try these fins.  First, they are a signature series product from Omer and Umberto Pelizzari, (who I will admit,  have been following his rise to prominence in the freediving world since the mid to late 1990’s), and second, they are an extremely high tech looking fin.  The way the blade is attached to the foot pocket is very unique with what they are calling a “water exhaust system” that bonds right into the rails along the side of the blade.  This new way of attaching a blade to the foot pocket can either look brilliant in they way it streamlines the connection point and avoids any turbulence, or completely over-engineered.  Either way it does look cool.

The next obvious difference between these and any other fin I have seen is that the angle of the blade is 29 degrees.  This is a much greater angle than any of the other fins in the test group.  The purpose of this angle is to help with the streamlining position of the blade with your foot in the “at rest” position.

The fin rails on the blades are very similar to the C4 rails and help to prevent fin leeway while swimming.  In other words they keep the maximum energy of your thrust in line with the direction you want to go.  This rail construction though great for line diving, inhibits sculling, so would possibly be a point against using them as a spearfishing fin.

I put on the Omer UP-F1’s and slipped into the water.  My first thought was, the flexibility of the blade and lack of resistance nearly felt like swimming with no fins on at all.  I actually had to get out and try the Mares Razor Carbons back on right away to compare.  The Mares fins are just slightly stiffer than the UP-F1’s because of the way that the Mares Rails are constructed, and the way they attach to the blade.

The “finless feel” of the UP-F1’s was a bit disorienting, and made me wonder how they were going to perform in the kick cycle count.  I started out with some easy pace 25 yard lengths, and immediately hit the 8 kick cycle mark.  The lack of feeling the water resistance was strange at first, but the power and efficiency seemed to be on par with the Mares Razor Carbons.

Sprint tests:

Having narrowed it down to my interest in either the Mares Razor Carbon, or the Omer UP-F1 carbon fiber fins, I decided to do a sprint test with both of them.  My reasoning for this was that without an immediate opportunity to test them at 30+ meters of depth, this was the closest I would be able to get to see how the blades performed under “high-force” conditions.  If you recall from earlier in the article I complained of flexible fins not having the power I desired to begin an ascent from depth in the first kick cycle.  I tested both sets of fins with several all out, full speed under water sprints across the 25 yard length of the pool.  The results were surprisingly conclusive.

I started with the Mares Razor Carbons, and did several 25 yard sprints under water with rests in between.  12.2, 12.4, 12.7, 12.9 seconds were the times I was able to hit wearing those fins.  I then switched to the Omer UP-F1’s and the results were 12.9, 13.0, 13.1, 13.4 seconds.  It seemed possible that even with the rests in between switching fins, I was getting tired and slowing down on my pool lengths, so I switched back to the Mares Razor Carbons for a second set of data.  12.3, 12.4, 12.6, 12.9 were the result of the second round of sprints with the Mares fins.

These results were conclusive.  I get more power out of the Mares Razor Carbon fins than the Omer UP-F1’s.  I consider the seven tenths of a second a fairly significant gap, which was completely unexpected after the nearly identical results on the kick cycle tests between the two different brands.


Photo of Mares Razor Carbon and Omer UP-F1 finsAfter the pool tests I was convinced that carbon fiber fins were the right choice as my next set of fins, and Mares Razor Carbons were the best of the sets I tested.  Performance of the Mares was equal to the Omer UP-F1’s on kick cycle tests, and significantly faster than the Omer on the sprint tests.  In other words both fins were equally efficient, but the Mares Razor Carbon fins delivered more power when required.

Interestingly enough, the Mares Razor  Carbon fins ($560.00 USD) come at a lower price point than the Omer UP-F1’s ($850.00 USD).  Since they scull well, and I have heard that they can take a beating on the rocks they would also make a good all around freediving and spearfishing fin.

The Omer UP-F1 fins are not a bad fin, and if I were looking for a more flexible blade to avoid stressing my ankle joints, or for any other reason, they would be one of my first choices.   If you are looking for a fin to help extend your limits of depth or distance though, I would highly recommend the Mares Razor Carbon fins.

If you have tried any of these fins, or other brands and have feedback on how you feel they perform, please leave a comment below.