After another steamy night trying to sleep on the boat last weekend, I bought one of these Amazon.com: Haier CPRB08XCJ 8000-BTU Portable Air Conditioner: Kitchen & Dining
... Man, I must be getting soft! But I'll say, we had a great night's sleep Sunday night.
I picked this up at the Super Target for $299.00. It is only 8000 BTU's, but the wife got up to change the setting during the night because she was too cold. I'm not sure how well it will cool during the daytime, but we spend little time inside the boat then anyway. It stows away easily in the V-Berth when not in use. I did not like the idea of a window unit stuck in the companionway or on top of the boat.
This unit has auto evaporation, so no need to empty water from the unit. You will need to run the hot exhaust to the outside. There is a fairly long expandable hose included. We already had a foamboard piece that fit in the companionway left by the PO. I got out a fillet knife and cut a hole for the hose to exit through so we could use it that night. I am going to buy a piece of wood to replace the bottom board that I can attach the hose to when the unit will be in use. It does draw 15 amps, so be careful what else you plan to use when the a/c is running.
This is a reasonable/affordable way to stay comfortable if you don't have the boat bucks to spend on an actual marine unit. I still feel a bit guilty though. I could have had those new halyards...but when I mentioned the idea about the ac unit to the wife, she said "let's go buy one"! Gotta keep the woman happy, right?