"Caribe" is our Hunter 27 Cherubini. Here in Florida you need AC cooling 8 months out of the year. For the longest time I have had the idea of installing an RV Air Conditioner on the cabin hatch opening behind the mast. The unit in question is a 13.5 BTU weighing 90 pounds and standing 13" tall. The required opening is 14" X 14" while the hatch opening is approximately 17" X 17". I have seen various boats with this set up but I'm wondering what the negatives may be. I would like for someone who has actually installed one of this units in a crusing boat to comment on it. I,m concerned with forward visibility, weather sealing, raising center of gravity, condensation drainage and stains. Would a frame have to be built to shrink the hatch opening? Would I have to drill through the cabin top and the cabin liner?Would this be a virtual permanent installation which would be costly to reverse if the unit breaks or I decide to take it out. I'm currently running a 5,200 BTU small window unit wich fits into a companionway board. We run a Honda 2000EU at anchor and it is very adequate but climbing over the AC unit to get in and out is annoying the admiral. It stores in the storm bunk. The RV unit in question with a heat strip and shipping costs is Approximately $525. This is a lot less than the carry-ons and the inboard units. Portable air conditioners have to be vented to the outside and are heavy to move and just as expensive. Comments and suggestions would be appreciated.