You will definitely need water! We were on a 450F last month (not Navigare) and she had a watermaker (factory installed - hooray!). There were only 4 of us and we used water like crazy (although we did have fresh water flush heads). NO water or services in Coral Bay. Only STJ option for fuel and water are the Cruz Bay fuel docks (can get busy with all the day charters in and out morning and late afternoon). They also have ice (only other ice option is Coral Bay). Think about trash disposal also.......