Apeks RK3 Fins

Trusted by military divers, special ops teams, coast guards, and public safety divers for decades — the Apeks RK3 is the benchmark rubber fin for serious underwater work. Built from ultra-rugged thermoplastic rubber with an oversized foot pocket designed to fit drysuit boots, the RK3 is as at home on a pebble beach as it is at 40 metres.

Whether you're kitting up in thick gloves on a cold UK shore dive or gearing up for a technical twinset dive, the RK3's spring straps make donning and doffing effortless. The short, wide vented blade delivers powerful forward thrust on the downstroke while shedding resistance on the upstroke — so you work smarter, not harder.

Key Features

• Oversized foot pocket — fits drysuit boots and thick wetsuit boots
• Spring straps as standard with custom-designed buckle for optimal positioning
• Short, wide vented blade for maximum thrust and manoeuvrability
• Vented design reduces upstroke resistance and eliminates blade vortexes
• Two large grommet holes for karabiner attachment — easy site access
• Simple push-pin spring replacement system
• Ultra-rugged construction for harsh environments, extreme temperatures, and heavy use
• Available in Standard and HD versions (see comparison below)

Standard vs HD — Which Should You Choose?

Sizing Note

The RK3 is available in Small, Medium, Large, and Super. We don't use shoe size ranges as they can be misleading — your environment matters more than your shoe size. A size 9 foot in a wetsuit boot takes up far less space than a size 9 in a rigid drysuit boot. If in doubt, contact us and we'll help you choose the right size.