Hi, Its all depends how much you want to spend ! I'm in the Opticron camp having had a pair of 8x42 BGA binoculars for about 10 years until this year when my car got broken into, still haven't replaced them. I also have 2 opticron scopes (60mm & 75mm) and an opticron monocular. They are not the best in the world but I do think they give good value for money. One thing I would be tempted by is getting nitrogen filled, as if they are likely to spend periods on the boat this will help with issues of condensation.
As others have commented, best to find somewhere with a range and try a few, because it doesn't matter how much they cost, if they are the wrong weight or size for you they will be little used. Good luck and happy spotting