• Updated version of our F1 Military Rubber Rocket fin, with a shorter and wider blade
• Ideal for use when training for Special Ops military programs
• Special blade curvature, varying degrees of flexibility and well positioned structural ribs for positive forward thrust with spring-like energy return
• Open vents and perforations on the blade efficiently channel water to the rear, adding power to every kick; quick release buckles for easy donning and doffing
• Open foot pocket designed to wear with dive booties

Based on IST's iconic F1—a favorite of the U.S. military—, the F4 provides power via a shorter, wider, but still flexible blade design.  Pierced fin construction with 3 deep vents to force water backwards, emulating the acceleration of three synchronized turbo-powered water jets.

Military fins from IST are excellent for open water dive missions, but also demonstrate their agility in assisting diver maneuverability within confined spaces.  The F4 is an especially good option for salvage and rescue divers who need to work where space is limited.

As you would expect and demand of a military fin, the F4 is durable and long-lasting, and compatible with IST’s famous universal clamp, stainless steel, coil-spring fin straps. 

The F4 is following in the proud tradition established by our F1, and is already a favorite with the U.S. Navy.