You will never convince me that a plug in portable cooler is a good solution. Brandon and G are right on target.
I would take 3 to 5 day boat trips with a 1/2 size refrigerator/freezer. The thing could never keep up with openings much less cool drinks and if you were not on shore power, running the engines or the generator it was not cooling. My old standard igloos were melting 5 to 6 bags a day in our larger coolers. I finally threw all those crap coolers out and bought a couple well insulated although expensive coolers call Icy-Tech. The ice now lasts for days. That turned out the be a great decision and many friends with off-shore boats followed suit.
Taking it one step further, since then I have been thinking of taking the powered refrigerator/freezer out of the boat and installing a larger ice maker in its place. Its a much better system for keeping things cool and it a better option than dealing with electrical solutions. Try adding dry ice if you need it to last even longer.
Last edited by srock; 02-05-2013 at 10:09 AM.