Another common issue is air conditioning. That is usually a trip ender in south fl and in the bahamas especially on modern euro styled boat with no natural ventilation. But in addition to regular maintenance there are steps you can take to maximize reliability, something unfortunately many builders don't. For instance many marine AC issues are caused by reduced flow in the sea water circuit. Often because the hose sizes are too small especially in manifolds. Or builders will use one pump for multiple units with no back ups. Upsizing hoses and manifolds is often easy and cheap. Adding an extra pump you can switch to by flipping a switch and a couple of valves is also an easy solution. Smaller boats have either self contained or splits. Loose one compressor and that room is done, if that's the main saloon chances are that summer trip to the Bahamas isn't happening... larger boats, above 50/55 these days usually are set up with chillers. If loose one chiller in the typical twin chiller system you will still have some cooling so the trip doesn't have to end.