The quick and simple answer could be JL Audio MHD900/5 + M200/2 or JL Audio M1000/5 + M600/6.
It's definitely a job for two amplifier chassis. But that is only a rough recommendation without having far more details about the system objectives, like if the primary focus is listening at the helm with all speakers audible at that location, or whole boat distribution, or if some speakers are relegated to zones, etc. Considering speaker location details is also very important in an amplifier(s) selection. For example, doubling/halving the wattage makes a +/- 3 dB difference, where as doubling/halving the distance makes a far greater +/- 6 dB difference, and orientation can even have a more profound difference in the power demands. Again, the above recommendation is based on the simplest criteria.