Binoculars
Marine

There are binoculars designed specifically for civilian and military use under harsh environmental conditions at sea. Hand held models will be 5× to 8× magnification, but with very large prism sets combined with eyepieces designed to give generous eye relief. This optical combination prevents the image vignetting or going dark when the binoculars are pitching and vibrating relative to the viewer's eyes due to a vessel's motion.

Marine binoculars often contain one or more features to aid in navigation on ships and boats.

Hand held marine binoculars typically feature:

Mariners also often deem an adequate low light performance of the optical combination important, explaining the many 7×50 hand held marine binoculars offerings featuring a large 7.14 mm exit pupil, which corresponds to the average pupil size of a youthful dark-adapted human eye in circumstances with no extraneous light.

Civilian and military ships can also use large, high-magnification binocular models with large objectives in fixed mountings.
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