Yes I agree that on a boat a 7x50 is better than a 10x50. Also with a bigger enlargement you get always less light on the image.
I have choosen this ones precisely by its superior quality with low light.
Nexus Marine Catalogue 2012 - Nexus - Page n° 56 - PDF Catalogues | Documentation | Boating Brochures
It is quite surprising, you actually seem to have a much brighter image at dusk through the binoculars than without them and that is odd. It takes also haze away. At night the image is also surprisingly bright, also brighter than without them.
I have posted already the model without compass, by mistake. I have the one with compass now and I owned one without compass for many years. I think the image quality is very similar, compass or not.