marine binoculars for adults, 10x50 rangefinder compass waterproof fogproof with low light vision bak4 prism fmc lens binocular for birdwatching boating hunting and navigation bnise the deep sea 10x50 waterproof floating binocular internal rangefinder & compass is made for all outdoor activities, but designed with boating and nautical enthusiasts in mind. with 10x magnification and excellent optics, these binoculars provide clear views of marine observation from dusk till dawn.