Whether DC (12 volt ) or AC (110v or 240v), I'd recommend that you choose a high capacity model ie. 60 l/ hr or higher. These will allow you to make plenty of fresh water when clean seawater is available. Often at anchor
in rivers, bays or harbours the quality of seawater varies according to the stage of the tide, so it's great to be able to make maximum use of the clean water on the high tide. This results in less filter clogging and strain on pumps, etc.
High capacity water makers have traditionally been AC or engine
belt powered. These days an inverter
backed by a decent house battery
bank allow AC water makers to be used without a genset. We have a 140 l/hr AC motor
powered Rainman installed and it runs easily on inverter
or Genset. I prefer the simplicity, economy and serviceability of these units over the more complicated and expensive electronically automated watermakers.