I am not sure I can answer your ? as I am not sure where your launching and what your Gallons per Hour are. I installed a flow meter on my boat to track GPH and save gas. My boat will travel flat out about 52 miles an hour but uses 22 gallons an hour with a 85 gallon tank. Now drop down to 42 it uses 15.6 gallons an hour. Drop it down to 34 and it uses 9 gallons a hour. So you would need to know your GPH and distance to calculate. If your not sure throw a couple of jerry cans full of gas on board . their should be plenty of places you could stop and get gas if needed.