What I can't beleive is someone spends millions of dollars on a boat and there is NO passive ventilation. Man I would hate to on the thing when the Aircon or Generator crapped out! Since I've never had the opportunity to look at any of the machinery I don't know, maybe each AirCon zone has a backup and maybe there is a generator backup. Still hate to be there when the shit hits the fan. However; my guess is you would quickly get the the next port on one of these babies.