Proper Props
Propellers potentially increase fuel efficiency by as much as 10% when matched to the right boat and purpose. Keep them clean, as growth will affect fuel economy (and slow down the boat). A dinged or broken propeller will also reduce fuel efficiency, so periodically check for damage.
Engine Upgrade
Newer models conserve fuel (or eliminate it).
Lighten Up
A clean boat drags less, and a lighter boat lessens the engine load. If it doesn’t belong, leave it behind! If you don’t need the shade, remove your vessel’s canvas and bimini top to reduce drag. As water weighs eight pounds per gallon and gasoline weighs six pounds per gallon, skip a full freshwater or fuel tank fill up for nearby adventures. (Keep the rule of thirds in mind: allocate one-third of your fuel for the outbound trip, one-third for the return, and have one-third in reserve.)
Spread Out
Evenly distribute your passengers to increase efficiency and instruct them not to all gather in one area while underway.
Know Your Waters
Check the forecast and plan outings around tides, currents, and wind. Besides being unpleasant and unsafe, rough conditions create fuel inefficiency.
Extra Efficiency
Avoid idling — fuel-injected engines don’t need time to warm up. When you exit a no wake zone, get on plane as soon as it is safe to do so. However, don’t speed! A smaller wake requires less gas, so a lower speed is both safer and more economical.