Deep Apnea Quadraxial 85cm Carbon Fiber Fin Blades

Overview

Deep Apnea Quadraxial 85cm Carbon Fiber Fin Blades are designed for freediving and spearfishing, combining responsive carbon fiber construction with controlled flex for efficient underwater propulsion. Their multilayer structure supports smooth surface swimming, precise movements while hunting, and powerful ascents with reduced kicking effort.

Quadraxial construction and blade response

The Quadraxial structure arranges carbon fibers in four orientations: 0°, +60°, 90°, and -60°. This multidirectional reinforcement helps resist torsional deformation, keeping the blade more stable as it bends and recovers during each kick.

Variable Parabolic Stiffness (VPS) uses the layered carbon construction to control how the blade flexes under load. As the blade bends and returns toward its original shape, it transfers energy into propulsion. This responsive action allows divers to maintain movement with smaller, controlled kicks, particularly useful when approaching fish or adjusting position underwater.

Stiffness selection

Choosing the appropriate stiffness depends on the diver's body weight, leg strength, and kicking technique. The blade should flex sufficiently during each kick to generate propulsion without excessive resistance. A blade that is too stiff can increase leg fatigue, while one that is too flexible may not provide adequate propulsion for the diver.

Foot pocket installation

Choose a Neritic, Neptonics, or Cressi foot pocket and the required Foot Pocket Size. Select No Foot Pocket for blades without foot pockets. Compatible foot pockets and the correct mounting configuration are required to use the blades as complete diving fins.

Proper mechanical attachment and compatible foot pockets are important for secure installation and warranty eligibility. Deep Apnea recommends approved foot pocket designs and restricts drilling practices that could compromise the blade structure.