Navy Blue is the most common. It's a very dark blue, almost black; all other Sunbrella blues are a lighter shade to some degree.
A dealer ordering the boat from Hunter could choose any fabric color for the canvas... if the dealer ordered canvas. It's always possible a prior owner added the canvas later. So while it is likely to be Navy Blue, it's not a guarantee.
Over 24 years I'd estimate that 95% of the canvas for Hunter owners is Navy Blue and Cadet Grey, with the occasional Pacific Blue on a handful of Cherubinis. Marine Blue is a new color and we haven't seen much demand for it yet.