Freshwater consumption absolutely dwarfs oil consumption. People also ask "if you can build long distance oil pipelines, can't you build long distance water pipelines?" It's not impossible, but it's not particularly affordable either because the value of water per liter is so much lower.
What about utilizing ocean currents? You deploy the collectors and eventually they end up somewhere close enough to be toed in without using much fuel. Deploy them at regular intervals and go pick them up as they get closer to shore. This is assuming such currents exist and will allow enough time for the collectors to collect enough water.
The big problem is I'll not be anywhere close to that level of production for a decade at least. Large scale is quite doable conceptually, but the financial requirements are nearly that of a desalinization plant itself. I need to work my way up to such production.
But to follow that line of thought, I've been investigating FPSOs [1] because of their transportation and "mobile factory" to service the individual stills while out in the "field".
