C4 Footpocket 200 white sole

The revolutionary C4 200 footpocket takes freediving and spearfishing fins a generation forward. Price per single footpocket.

Technical features

• European sizes: 36/37, 38/39, 40/41, 41/42, 42/43, 43/44, 44/45
• US/Canada sizes: 4/5, 5.5/6, 7.5/8.5, 8.5/9, 9/9.5, 9.5/10.5, 11.5/12
• Weight: 180 g (6.3 oz) (size 41/42)
• Upper material: thermoplastic elastomer
• Upper hardness: Medium 74 ShA (sizes 41/42-44/45), Soft 65 ShA (sizes 36/37-40/41)
• Sole material: polypropylene, flexural modulus 1250 MPa
• Adjustable biomechanics on 3 positions: Soft, Medium, Hard
• Foot preforming: 3°
• Sole colour: white, red, green
• Compatible only with 200-series blades: L-1090 Apnea, L-1090 Betta, L-1090 Pesca, S-990, S-990 Camu

C4 200: zero fatigue

The 200 fins are built on modified biomechanics designed for minimum energy consumption. In freediving, performance depends on how much energy is needed to move forward while finning: the more energy the fins require, the more fatigue and the lower the performance and safety. Traditional fins, with blades locked or glued inside the footpocket, introduce biomechanical limitations that create extra fatigue.

Posture and hydrodynamics

In traditional fins, the blades extend beyond the toes, sitting on a different plane from the body's neutral axis: this forces the diver to compensate by leaning the torso forward, worsening the shape coefficient and increasing fatigue. In the 200, the blade is aligned under the metatarsal: the diver stays upright, aligned with the direction of travel, with a perfectly balanced stroke and no extra resistance caused by posture. Compared to C4's historic 2006 Mustang fins — the world's first with the blade aligned under the metatarsal — the 200 also eliminates the large rigid connection area between shoe and blade typical of traditional fins, thanks to a minimal-size connection and blades with controlled curvature close to the foot.

Reduced mass

The force needed to move the fins is directly proportional to their mass: in the alternating finning motion, each cycle involves 4 direction reversals that require re-accelerating the mass. The 200 footpocket weighs 189 g in size 42-43, about half or a third of traditional footpockets: a difference that, multiplied across the thousands of kicks in a day of diving, translates into a significant saving in fatigue.

Personalisation

The blades, positioned under the metatarsal, can be adjusted to three distinct positions (Soft, Medium, Hard) to match the stroke to individual physical characteristics. There is no single optimal position for everyone: the best setting is found by trying each one, and it's the one that feels the most agile and least tiring. The blades don't change their thrust based on the setting chosen, but the perceived hardness varies due to the different lever arm.

Reliability and construction

The 200 series has been tested for over 18 months by an international team of divers and in the lab, with fatigue tests of over 1.6 million complete cycles applying three times the force of a human. Fastening uses just two longitudinal screws, with a polyurethane shock absorber placed between blade and footpocket to absorb stress. The 200-series blades are dedicated and not interchangeable with other C4 models: the attachment point, being minimal in size, is heavily stressed and specifically engineered for this use; adapting incompatible blades is strongly discouraged as it is risky.

The footpocket is made by overmoulding a thin, sturdy, self-shaping thermoplastic elastomer upper onto a rigid polypropylene sole. The 6 threaded bushings that allow the blade position to be adjusted are applied directly through co-moulding, and the blade fixing screws feature anti-loosening thread lock. The blades' 3D-shaped water rails are applied using the overmoulding technique developed by C4 specifically for the 200 series; the O.P.S. (Over-moulding Protection System) shaping protects the blade from impacts and unwanted damage.

Comfort

The upper, self-shaping thanks to C4's anatomical design and calibrated thicknesses, adapts to the shape of the right or left foot, accommodating it without pressure points in the 3° anatomical preforming. The rigid sole transmits all the applied energy efficiently.