CH Smith Marine has selected the best binoculars, suited for your outdoor and boating use. To avoid moisture (and salt) penetration under these conditions, that would result in fogging of the interior glass during temperature changes; we reckon the best binoculars are waterproof: nitrogen filled/purged and O-ring sealed .
Binocular specifications come with two sets of numbers, such as 7x50 or 10x50 to describe the power (magnification) Vs the diameter (in mm) of the front lens. A 7x50 pair of binoculars for example, has a magnification of 7 (7x), so an object will appear 7 times closer than reality, and a front lens with a 50mm aperture. Larger apertures mean increased light gathering ability, but size is then a trade-off with weight and chunkiness.
Higher magnification comes with a reduced field of view (FOV) making it more difficult to find and keep distant objects centred while bouncing around on the water. So when out on the water, increased power does mean the best binocular! Mariners often consider 7x50 binoculars to give the best functionality all round.
The prisms (porro prisms or roof prisms) are the guts of your binoculars, but not all prisms are created equal. At CH Smith we stock the Gerber marine binoculars with BAK-4 porro prisms. They're made from superior optical glass to produce clearer images.
Marine binoculars shouldn't be considered a "nice to have" item on your boat. Would you leave dock without your life jackets or VHF radio?, likewise binoculars should be considered an essential item of boat safety and navigation equipment.