[capta]

First crossing from Frisco to Hawaii on my own boat, we tried to make spaghetti with sea water. Every other crossing, be it on a 600 foot ship or a 65 foot ketch, the only thing I'd had to do with food was as a consumer, so I knew nothing about preparation at sea.
Not a long (about 35 minutes actually), but a really frustrating story later, especially when the crew is letting you know they are a tad hungry, the pasta was completely inedible. A few weeks of trying to get the ratio of sweet water to sea water correct was just as frustrating and I have never attempted to use sea water for cooking, ever again. It probably wouldn't have saved a cup per gallon of fresh water, anyway. Boiling crab and lobster yes, but actually cooking, not so much.
We were taught a Fijian recipe for Moray eel that requires cooking the eel in sea water five separate times, to wash out the toxins, before one can begin to cook in earnest, but that's probably not what you are looking for.