The only two binoculars rated as SUPERIOR by Practical Sailor magazine, were the Fujinon Polaris and the Zeiss 7x50s (which cost about $500 more). In fact Fujinon was rated best in dim light conditions. Thanks to a proprietary zirconium oxide, electron beam coating (EBC) process, they are able to transmit an incredible 95% of the light striking their objective lens. They are the brightest binoculars in the world in critical low-light dawn and dusk situations. Their housings are super-rugged lightweight aluminum alloy which are rubber coated. This makes the binoculars easier to hold, and helps to prevent damage if dropped. All models are 100% waterproof and nitrogen filled to prevent fogging and mold. They all carry a limited lifetime warranty.
We chose the 7×50 specification because this has long been considered to be optimum for marine use. This is because of excellent light gathering and maximum magnification useable on a moving platform.
You can buy cheaper binoculars, but they won’t be as optically good or bright, durable, and resistant to fogging and mold. Because these binoculars will last much longer than cheap ones, they can be thought of as actually more economical in the long run. The bonus is that all the while you will be enjoying the best vision in the world.