C4 Carbon launches new freediving fins looking more and more towards performance. The new offer sees the C4 SPORTECH fins with glass fiber and carbon fiber blades, and with open heel foot pocket both in silicone and natural rubber, an option for the first time on the market. Also, for best performance possible, the new extraordinary fins by C4 Carbon, the C4 PROTECH fins are born. We have received the C4 SPORTECH both with glass and carbon fiber blades and silicone foot pockets. Here is our first X-Rays analysis.
Design and application
Easy for traveling
The C4 SPORTECH fins are made so that the blade is dismountable, and very easily, from the foot pocket. This is thanks to the single screw solution by C4 and the absence of side rails. A very comfortable solution which makes the process extremely fast. In such way traveling with the C4 SPORTECH fins is very easy storing them without the need of very long bags.
Thought for “comfortable performance”
The C4 SPORTECH fins are thought indeed for very good performance but, differently to the C4 PROTECH, which indeed are designed for top performance, the SPORTECH focus on comfort, ease of use, lightness on the legs. The idea is to have good performing dismountable freediving fins that can be used with fun and full comfort at any time even with long diving or training sessions.
Foot pockets
The foot pockets of the C4 SPORTECH fins are really nicely designed with a great look, made of very neat lines and alternation of matt and glossy surfaces of the silicone. The foot pockets, just as the blades, have a left and right design. This permits to have the internal part of the foot pocket reproducing the shape of the foot, especially in the plantar arch and the tip. Such solution is thought for the best wrapping of the foot, but at the same time a great comfort. Just as for all the top performance freediving fins foot pockets, the ones of the C4 SPORTECH have open heels. The different offers of silicone and natural rubber are there to permit the customer the best personal choice: high softness and maximum comfort silicone, medium softness natural rubber for best reactivity and good comfort. In general, the silicone feels very soft, and the rear band in the open heel back of the foot pocket is narrower than other products on the market, to act more gently.
Blades
We have received the Soft version of the blades, both in glass fiber and in carbon fiber. These feel soft and easily flexible, and also very light. The glass fiber solution is intended for a very smooth and progressive kick, ideal for maximum energetic saving. The carbon fiber solution evidently is intended for best reactivity and performance. The extreme lightness of the blades is the philosophy brought forward by C4 Carbon since years, and optimized more recently with fins that both in the foot pocket and the blade are among the lightest on the market. An example are the C4 FBG Umberto Pelizzari glass fiber blade fins, winner this year of the 2025 Best Choice by Apnea Passion in their category. The available stiffnesses are Soft and Medium.
Weights and sizes
Weight of foot pocket and blades
The 41-43 C4 silicone foot pocket weighs, according to our measures, 475 grams, including the screw and pads for the connection. The glass fiber Soft blade weighs 290 grams, while the carbon fiber Soft blade goes down to 230 grams.
Dimensions of the blades
Both the glass fiber and the carbon fiber blades, having the same dimensions, measure 74 cm in total length, with the concave central part of the flap being 2.5 cm deep. The width inside the water rails is 19 cm, while the total width including them is 19.5 cm. The water rail are quite narrow, 1.5 cm high, and run all along the sides of the blades. This helps channel the water, but also protect the blades from shocks.
Offer and prices
Stiffness and sizes
As anticipated, the C4 SPORTECH freediving fins are offered in Soft and Medium stiffness, both for the glass fiber and the carbon fiber blade solutions. The sizes of the foot pockets are 35-37, 37-39, 39-41, 41-43, 43-45, 45-47 in the silicone version and 36-38, 38-40, 40-42, 42-44, 44-46 in natural rubber.
Prices
Prices of the C4 SPORTECH fins will be 460€ for the carbon fiber and 270€ for the glass fiber blade, independently from the choice of silicone or natural rubber foot pockets.
Conclusions
C4 Carbon enters the performance freediving sector with a huge offer, going from the C4 SPORTECH glass fiber fins, to the SPORTECH carbon fiber, and up to the C4 PROTECH (that we will present soon in a separate article). The C4 SPORTECH are intended both for Dynamic and CWT apnea. The C4 SPORTECH with the double option of the silicone and natural rubber foot pockets and their asymmetrical design for left and right foot, are thought for great comfort with high performance. Having long freediving sessions with great performance and comfort is now possible. The dismountable solution is an additional plus in comfort for transportation and an option to change blades, in material and stiffness, without buying new foot pockets. The price of the glass fiber solution appears extremely interesting.
Our top testers, Luciano Morelli and Michele Tomasi, have already tested the C4 SPORTECH fins in glass and carbon fiber with silicone foot pockets at the fantastic Y-40 and we will soon publish the review.
