range of larger boats?

Question
Hi. I am trying to write a screenplay, and for it I need to know how far a speedboat or motorboat can travel. I am led to believe that even a large speedboat or motorboat (maybe something in the range of thirty/forty feet long or thereabouts? - is that a pretty normal size?) can travel well above 60 mph. My question is, how far can a large boat travel on a full tank of fuel? Is it possible to go 100 miles or more with some type of large motorboat? (As you can see, I don't really know anything about this field; any info at all would be very helpful.) Thanks a lot for your help and time.

Answer
first of all, yes boats in the 40' range can go as fast as 60 miles per hour. the range is determined by the amount of fuel they carry and the horsepower. the average boats burn approximately 1 to 2 gallons per mile, per engine. so if you carry 400 gallons of usable fuel, you would have an approximate range of 100 miles. also if you get a magazine like yachts international or power and motoryacht, they give specific ranges for a variety of yachts. you can go to powerandmotoryacht.com to get it on the web. hope this helps.