Just my opinion - your boat has 'grey' non-skid which is pretty ideal for less 'glare' and sun reflection. The amount of gloss on relatively little surface area outside of the non-skid wont make much difference. Gloss paint is easier to clean.
Just another opinion - single part paints on decks and flat surfaces in full exposure to the sun dont last that long before they become 'chalky' and sun damaged. I suggest you consider a 2 part urethane for this application --- as such are 'harder', impervious to chemicals / staining, and less subject to abrasion than a single part.
For 2-part paints, they do have a high learning curve to assure a 'decent' flat surface ... do websearch for "Don Casey + 2 part paint + topsides" for some good advice .... using a flat glass plate to insure the proper amount of thinner to arrive at a 'dazzling' flat surface almost to the appearance of a sprayed on finish.
