As Carmel says Aquatica would probably use a crane at Fertilia to lift out. I have absolutely no connection with Pinna at Bosa but would recommend as they are very professional, they have their own travel hoist ( 65t ), you can do your own work and no problem to stay on board. It is an easy walk...
Re Bosa, The channel has been dredged and a sea wall built in the last few years. I have taken my boat to be lifted each year with a draft of 2.5m with no problem.
Locals only drink bottled water all over Sardinia. As stated above, it is very cheap try Eurospin. The tap water is fine for anything else, tea,coffee etc.
You should try Bosa, about 42kms S of Alghero. Excellent yard with travel hoist, good rates, very professional and allow you to do your own work. I have the boat lifted there every year.