The thing about binos is that the 7X 50, 8 X 40 or whatever is only half the story.
The magnification and field of vision are important of course but so is the actual physical size of the outer lense, the bigger the better as they capture more light and of course give better sharper viewing and are much better in poor light conditions.
When I was a sea, one of my skippers had a pair of Zeiss binos that he had taken from a U-Boat Captain during the war (& yes he had sunk it as an RNR Commander). They were huge at least twice the size of any other pair I've ever seen. The clarity and the way one could even use them at night was amazing.
So if buying binos look for the largest outer lense you can find, they may be bulkier, but then you are not going to be taking them to the opera are you!
For use on a boat, the weight of the binos is important as well, the heavier the better, if they are too light then they are veryy difficult to keep steady and aimed on a target as the boat bobbles around. Heavier = more inertia = easier to keep steady!