Issues with a projector, especially a mini LED one would mainly amount to light control of the room. The interior of a boat can be pretty bright with white fiberglass surfaces and windows. You would need complete light control for a projector setup. Secondly is the screen size compared to your seating distance, check THIS
out to calculate what size screen you should have regardless of technology.
Frequency Response: Sat: 150Hz-23kHz; Subwoofer: 36Hz-180Hz +/- 3dB
Crossover Point: 3.5 kHz
Power Handling: Sat & Center: 240 Watts
Recommended Amplifier Power: 20 - 100 Watts RMS (Continous)
Impedance: 8-ohm compatible
Subwoofer Variable Low Pass Filter: 40Hz-150Hz
Tweeter: 0.5-inch (12.7mm) hyperbolic aluminum dome
Midrange: 2.5-inch (63.5mm) high-excursion aluminum cone
Woofer: 8-inch (20 cm) Injection molded cone with Ribbed Elliptical surround
Dimensions: Sat: 4.7 x 3.5 x 3.5in; Center: 3.5 x 5.9 x 3.5in; Subwoofer: 12.7 x 10.5 x 12.3in
Weight: Sat: 1.6 lbs; Center: 1.9 lbs; Subwoofer: 16 lbs
You can see the dimensions there, optimally you would have the port and the driver of the sub open to the cabin atmosphere but on a sailboat just getting it to fit anywhere would be a good start. do you have any interior pictures of your boat?