Pelizzari and C4: Champions back together

Umberto Pelizzari and Marco Bonfanti developing the new C4 Umberto Pelizzari fins

Umberto Pelizzari and C4 Carbon, with Marco Bonfanti, have already worked together many years ago, in the 90s. From 1992 to 2000 the “Carbon Company” and the Italian Champion conquered freediving records with the first and only, at the time, carbon fiber blade fins. In ’92 Pelizzari was sponsored Omer-Sporasub, and the following years Cressi, but he was permitted to use C4 fins. Today the “two” are back together with a new challenge: to lead also in the polymer blade fins sector, where materials have improved enormously and competition between big companies is harsh. With the new C4 Umberto Pelizzari fins the winning couple seems to have set once more new standards! A top-quality and performance foot-pocket together with an advanced polymer blade, potentially represent the new point of reference of the market. Before proceeding with the independent test that Apneapassion will bring forward, let’s analyze in details all the technical characteristics of these extremely interesting fins.

Umberto Pelizzari: “We wanted to design fins that could give extremely high performance, but were affordable by everyone. The polymer blade fins were the natural choice. I am today impressed, almost astonished, by the incredible thrust that the C4 Umberto Pelizzari fins generate…and it is not only my opinion, other athletes that have tested them have given the same feedback”.

Marco Bonfanti: “The 200 series fins have taught us how the modified bio-mechanic, meaning to have a fin as an effective extension of the leg and not simply a thrust blade, determines extreme improvements. We have transferred these notions, which are not specific of a single material, and much thanks to Umberto, in the polymer blade fins C4 Umberto Pelizzari. The result is excellent thrust and great speed with minimal effort, thanks to calibrated variable thicknesses of the blade which generate “reversed” flexion curves, meaning a particular and complex overturned parable”.

C4 250 foot-pocket

C4 has launched in the years many different models of foot-pockets, among which the revolutionary asymmetrical C4 Mustang, and then the 300, 400 and 200. The last three have shown the extreme focus on force transmission and weight reduction. A fine-tuning of comfort has been obtained and evolved in the more recent 200 and now in the totally new C4 250 foot-pocket. Putting together efficient force transmission, reduced weight and high comfort, C4 with the 250 foot-pocket has set the bases for a point of reference result.

Rigid sole

The best way to transmit the force from the foot to the blade is to utilize a rigid sole, already present on the 300 and also on the 200 foot-pockets. The C4 250 has a rigid sole in polypropylene co-moulded in the foot-pocket, a solution that requires an advanced design and top-level manufacturing systems. The preformed angle is the traditional 3° by C4.

Soft thermo-rubber

To guarantee the best comfort, the C4 250 is produced with a special thermo-rubber compound. The use of very soft but resistant thermo-plastic material is possible thanks to the rigid sole. The softness of this material gives extremely high comfort, permitting the use also without socks. Excellent ease of donning and doffing of these foot-pockets completes the top comfort features.

Extremely reduced weight

With the weight of only 247 grams (255 grams measured by AP) in the size 41/42, the third goal has been evidently well achieved! Believe it or not, less weight, even in the water, definitely determines less fatigue, especially during long sessions. Maybe something not perceivable by the less experienced freedivers and spearos, but indeed very important. Whether it is a freediving session or a long spearfishing day, the limited effort to move the fins determines reduced tiredness at the end of the session or the spearfishing day.

Additional pluses

The lateral rails reduced to the minimum (less than 3 cm) are something that C4 “invented” in 2006 with the launch of the Mustang foot-pockets. The reduced presence of lateral horns of the foot-pocket produces the best performance of the blade, as they do not interfere with its flexibility. The result is also an extremely easy and fast substitution of the blade when needed, even during the same diving session. To ensure the best connection between the C4 250 foot-pocket and the polymer (or carbon fiber) blade, C4 has designed an extremely refined locking system. A single large-diameter stainless steel screw connects to a big brass nut embedded in a generous size plastic element. The screw has an Allen head size 4 and is complete with a threadlocker.

Advanced polymer blade

C4 Umberto Pelizzari fins with 250 foot-pocket and advanced polymer blades

The optimal result is obtainable only thanks to the coupling of a top-quality foot-pocket to an extremely high-performing blade. The new C4 Umberto Pelizzari indeed are designed with blades that put together all elements needed: quality material selection, design, top-end production and unbeatable resistance.

Top quality materials and differentiated thickness for the C4 Umberto Pelizzari


To obtain both softness, high elastic return and strong resistance to breaking, the design and material of the blade are key features. C4 has selected and tested a high number of polymers, choosing two blends, one for the Soft version and one for the Medium stiffness blades. These two solutions guarantee extremely high performance and resistance, and are well more expensive than traditional polymers.

Integrated water rails

A key element and plus of the C4 Umberto Pelizzari fins is the fact that the water rails are over-moulded on the blades. The length (30.2* cm), the variable height (max 17.8* mm), the thickness (3.3* mm) and the material (thermo rubber) have been another main feature of these blades. The result is a blade that works perfectly with no interference from the water rails, but maximum control on lateral sliding of the fin during the kick.

(*AP measured)


The care in the design is perceivable immediately. The blade features a central smooth and glossy band which widens from the foot-pocket to the tip of the blade. On the sides, the surface has a carbon fiber finish look. On the back side of the blade, the finish of the surface is exactly the opposite.

The tip of the blade has a profile that recalls that of a whale’s tail. The blade is 59 cm long at the center and 62.5 cm laterally. The measure takes into consideration the length from the tip of the foot-pocket to the end of the blade. The total maximum length of the blade is 79.5 cm, while the total maximum length of the fin, so including the foot-pocket, is 91 cm.

C4 Umberto Pelizzari whale tail profile tip

Two long nerves are present laterally on both surfaces of the blade, but are 5 cm longer on the top side. On the other side of the blade there is an additional central nerve which runs almost all along the length of the blade. On the back area just before and after the tip of the foot-pocket there are two 16 cm long nerves, of large (15 mm) and tall (9 mm) dimensions, with an almost triangular section. The thickness measured by AP in front of the foot-pocket is 3.4 mm, and goes down to 1.6 mm at the tip of the blade.

C4 Umberto Pelizzari inferior nerves

The angle of the blade is 29° which added to the 3° angle of the C4 250 foot-pocket brings the total to 32°.

Record reduced weight

Today the C4 Umberto Pelizzari fins are by far the lightest on the market for long polymer blade fins. They are indicated to weigh less than 1200 grams a pair (1290 grams the measure by AP). The weight is therefore well below key competitors such as the Salvimar Speeder and the Cressi Turbo Impulse.

Research and development with Pelizzari

More than a year ago, C4 has started the project of the new 250 foot-pockets. The idea was to create a product featuring an extremely reduced weight, like the 300, but with improved comfort and a rigid sole to perfectly transmit the force from the foot to the blade.

The C4 250 were initially only to be matched with carbon fiber blades. Then came the involvement of Umberto Pelizzari in the project, a full involvement, well beyond the simple image of the Champion. Deep feedback was taken from Umberto and transferred to the C4 design team for the development of the 250 foot-pockets with carbon fiber blades. Soon an additional road was taken. The aim became to design a fin that could offer top level performance for ALL freedivers and spearos. This meant also having a very accessible price, and so led to a polymer blade fin.

Performance testing

Starting from mathematical models, the development of the C4 Umberto Pelizzari fins has followed a very practical and empiric path. Testing in the pool, at the world renown Y-40 pool and at sea, has been the base for the evolution of such fins. Thanks to the full involvement of Umberto Pelizzari, but also in general of the C4 athletes team, the prototypes of the blades were manufactured, then modified to try different solutions. Deep testing has been conducted to find the best shape and length for the water rails of the blades and lateral rails of the 250 foot-pockets.

Testing has been led at the Tenerife Top training Center, using their swimming flute, an ergometric pool. This system produces a constant flow at different set speeds. Diving in such flow allows to evaluate the thrust generated by the fins. Eventually also the effort needed to maintain a certain speed in the water is emasured. The images of the bending of the fins also indicate the correct functioning and control. The use of mathematical models helps evaluate the final efficiency of the fins.

After that, vertical dives at the Y-40 and at sea have been evaluated. So the fins optimized to perform in such conditions. The water rails have been additionally fine-tuned, and so have the lateral rails of the 250 foot-pockets. Two blade hardness have been defined, and again the testing has continued.

Resistance testing

Not only was the research and development done on the performance side. The C4 Umberto Pelizzari fins have been tested for a long time also utilizing the mechanical arm (or leg!) present at the pool at the C4 headquarters. The first prototypes lasted only a few days with the robot working 24 hours. Finally the result was a test that lasted more than 5 consecutive weeks. This means more than 840 hours of “finning”!!!

Availability and price

The C4 Umberto Pelizzari fins will be available at shops in Europe and around the world starting the 27th of February. The foot-pocket sizes available initially will be 41/42, 42/43, 43/44. By mid March sizes 40/41 and 44/45 will be available for purchase. Finally, starting mid of April, the sizes 36/37,38/39 and 46/47 will complete the offer of a really wide number of sizes. The amazing launch price of these extraordinary fins on the European market is only 99 €.