At the beginning of the 90s a tight cooperation between the company and a young unknown athlete begins with the objective of discovering the limits of carbon fiber fins. This athlete, who soon becomes very popular, is Umberto Pellizzari. Pellizzari, during his outstanding and very long sports career, will always use C4 carbon fiber fin blades for all his World Records in constant ballast.

This is the time of AIR-ONE and JOKER frames and forks drawing new streamlined shapes harmonizing the load distribution. JOKER frame has a special cantilever seat with a brand new design. The AIR-ONE design introduces a partial seat tube wing section.
Constant profile water rails are created for scuba diving fins, but they are then used for any kind of fin, as nowadays commonly occurs.
The Road Cycling world Championship is organized in Oslo. The Swiss national team, ‘SUISSE CYCLING TEAM’ finishes in 3rd position in the 100Km team trial race, using C4 frames and forks.

C4 is 10 years old. Thanks to an optimized project, CLASS is the first one kilo series frame. In 1999 the CLASS 99 will weigh only 916 g.

Presented in January, Vyrus, is the first monocoque with seat integrated frame and a special seat tube position and angle. This allows the seat adjustment without modifying proportions of the seat and the handlebar.
In freediving, Martin Stepanek’s reaches -93mt in constant ballast using standard FALCON fins. This is the new World Record for the bi-fins, unbeaten till now.

C4 is twenty years old. Fins revolution’s name is Mustang. Mustang fins feature a new criteria never used before. The new blades inclined at 24°, paired with C4 anatomical and preformed footpockets inclined at 3°, bring the total inclination between the foot and the blade at 27°. The footpockets are also adjustable and feature a left and right shoe. To optimise energy consumption, Mustang fins allow to apply force on the blade from underneath the metatarsus, the ideal point of strength. They don’t have energy absorbing spars, they feature parabolic curve water rails and the flap terminal is easily removable.
Mr.Carbon is a new entry in the speargun family featuring a brand new design. Mr.Carbon has a streamlined front position for a better grip and a kit for adaptation of the handle. Natalia Bonfanti is appointed marketing and communication manager and, thanks to her great contribution, C4 reaches world fame.

Similar to Mustang blades, but manufactured with less expensive materials, the first plastic Wahoo fin blades are produced. Wahoo fins feature hydrodynamic overmolded water rails.

Carbon fiber becomes stiffer, and T700 fibers innovate the manufacturing of all C4 products, thus increasing by 40% the common applied standards. Water rails become VGR (Variable Geometry Rails ) adapting their shapes to water speed and volumes for each blade section. Urukay, the new speargun, feature an advanced design and, as in any creation, its materials are only a part of the performance, the real difference is made by how they are used.

SKORPIOsub brand - Natalia Bonfanti’s brainchild – is created to offer existing solutions at competitive prices. C4 introduces the first monofin model: the Monoflap VGR, which is, as usual, out of the ordinary. The Joker 410, a modular carbon monocoque speargun, is introduced. Its special design combines the technique of the single shell structure made from 100% carbon fiber with the creation of several measurements through the regulation of a mobile part.

Blade fins carbon fiber is constantly evolving. The new carbon fiber with large squares of over 12 mm increases blades resistance and reduces energy absorption thanks to fiber interlacing. The 729 MUSTANG are the fourth evolution of the Mustang project born in 2006. The new inclination of the blades is 29° (+3°shoe). The 729 MUSTANG are equipped with shaped water rails, and with progressive deformation EVO, patented by C4. EVO water rails are fitted with a new variable profile that channels water on the blades in the best possible way. The new 729RED Falcon and 729BLUE Flap blade fins are introduced. They feature a 29° inclination angle with increased dimensions and they stand as the evolution of previous models.

Mustang HT blade fins, the fifth evolution of the original project, manufactured in a new type of “Big Square” carbon fiber, are introduced. This special "BigSquare” carbon fiber, with squares of 2,5cm, optimizes a more compact composite fiber, with much lower crisscrossing of the strands for high elastic return, reducing energy dispersion. All "BigSquare" blades offer a mechanical reaction never seen before, a higher stiffness capacity thus reducing physical efforts.

A new and important era for C4 begins. The Ciceri family, who have previously owned the company Omersub and have been absent from the market for five years, return to the diving industry by acquiring the majority of shares of C4 Srl.
In the same year, C4 introduces a catalogue filled with new products such as: the new footpocket 400, a mask, a snorkel, belts and bags.