Mares X-Stream Open Heel Fins The lightest scuba fin on the market. The X-Stream is one of the most decorated fins in recreational scuba history, and for good reason: it delivers powerful, efficient propulsion without punishing your legs. Whether you're on your first open-water checkout dive or hitting 100+ dives a year, the X-Stream keeps up. Mares engineered the X-Stream around two proprietary technologies that work together to convert leg effort directly into forward momentum: OPB (Optimized Pivoting Blade) Technology — The blade continuously self-adjusts to its optimal angle during each kick cycle, eliminating wasted drag on the recovery stroke. Channel Thrust Technology — Ribbed channels along the blade direct water flow rearward in a controlled stream rather than dispersing it, producing measurably more thrust per kick. The open-heel design pairs with any dive boot (Bare 5mm S-Flex boots are a natural match), and the bungee strap system means you can pull these on and off at the surface without wrestling with buckles. ⭐ Staff Favorite "When I was working as a professional underwater photographer and videographer in Sharm El Sheikh, my fins weren't a preference — they were a tool I staked my livelihood on. Shooting on the Sinai Peninsula means dealing with some of the strongest currents in the world. I needed to push into them hard, hold position to frame a shot, fin sideways, and yes — float backwards when a diver was coming toward me and I needed to keep them in frame. I also traveled constantly, and every gram in my kit was a negotiation. The X-Stream gave me everything: real power when the current wanted to take me, the blade responsiveness to maneuver precisely when the moment demanded it, and a weight I could actually justify in a bag full of camera gear. I've dived a lot of fins. This is the one I kept coming back to — and the one we've trusted at OTA for years." — Jeanne Cinquegrana, PADI IDC Staff Instructor & Aquatics Director | OTA Scuba & Swim, Katy TX Technical Specifications Specification Detail Blade Technology OPB (Optimized Pivoting Blade) + Channel Thrust Heel System Open heel with bungee strap Foot Pocket Material Thermoplastic rubber — ergonomic, multi-density Blade Material Polypropylene with elastomer inserts Available Colors Ocean Blue, Black, White, Yellow, Orange, Pink Available Sizes XSM, SML, REG, XLG (see size chart) Boot Compatibility 3–7mm dive boots; bungee strap adjusts to fit Certifications CE EN 13319 💡 Pro Tip from Our Instructors Fit matters more than most divers realize with the X-Stream. The right size depends not just on your foot, but on the boot you're pairing it with — and soft-sole boots fit differently in this foot pocket than hard-sole boots do. A soft-sole boot compresses into the pocket and can run a full size smaller than expected; a hard-sole boot holds its shape and sizes more true. Get this wrong and you'll either be fighting the fin all dive or losing it on a kick. Call us before you order — our team sizes divers for fins every day and we'll make sure you get it right the first time. 855-OTA-DIVE (855-682-3483)
