Originally, the ship only has a central heating system. That's just fine for fishing in the North Sea but won't do in the tropics.
We plan to settle for a chiller system like those of Webasto Marine Airconditioning, a traditional chiller system (using chilled water and air handlers in each room). A diagram is shown below, courtesy of a French Webasto dealer website.
Their Dutch site is www.webasto.nl.
We're looking at a 3-compresor 180.000 btu unit.