On Nirvana all 4 of the diesel fills are BELOW deck in the saloon. Also the fills on the 2 tanks I didn't replace are small diamater so you have to be very careful not to burp fuel. It takes a LONG time to fill the port tanks.

The good news is the we carry almost 200 gallons, so we don't need to hit the fuel dock very often. On our app 4000 mile Mexico cruise we only had to fuel up 5 times -- Barra, PV, La Paz, La Paz, and Cabo to top up for the bash home.