Magnifying Life Does, Indeed, Include Sea Life. And These Are Just The Binoculars To Do It. Our Legendary 7x50mm Marine Binoculars Are A Premier Choice For Spotting Marinas, Deadheads Or The Fisherman's Best Friend, Feeding Birds. Built To Withstand Rugged Nautical Conditions, They Are Nitrogen-purged To Provide Reliable Waterproof/fogproof Performance. The 13-7500 And 13-7501 Models Are Even Hermetically Sealed To Further Assure That No Moisture Creeps Impressive Light Transmission From Bak-4 Porro Prisms, Multi-coated Optics And Large Uv-coated Objective Lenses Brighten Images From Dusk To Dawn. And, All Three Models Not Only Float, But Easy-grip Rubber Armoring Protects And Provides A Secure Hold Should Things Get Rough. Always Nice, Should An UnExpected Swell Or Throttle Burst Take You By Surprise.