Any planning boat will get its best economy at hull speed. Typically a 60 footer will burn about 12gph at 10kts... a 70footer about 18gph and an...
If operating as an un inspected vessel (up to 6 pax under 100GT, up to 12 pax over 100GT) there are very few additions safety gear requirement...
You need to measure the size of the platform which will always be less than the beam of the boat. Remember beam is measured at the widest point...