Fuel Capacity Planning

Fuel Capacity Planning

Fuel capacity planning has turned into a moving target with all the range calculator tools, extended tank options, and bladder fuel debates flying around. As someone who has planned passages where running out of fuel meant calling for a tow — or worse, drifting — I figured out how to handle figuring out how much fuel you actually need versus how much you think you need. Today, I will share it all with you.

Here’s what most people get wrong about fuel planning: they calculate their range based on calm water, ideal RPM, and a clean bottom. Real-world fuel burn is always higher. Current, wind, sea state, bottom growth, and generator usage all eat into your range. I use a rule of thumb now — whatever the math says I need, I add 30% and then make sure I still have a reserve beyond that. It’s saved me more than once.

Getting Fuel Planning Right for Your Cruising

Probably should have led with this material, openly. Prepare your vessel by running actual fuel consumption tests at different RPMs and sea states — published specs from the manufacturer are starting points, not gospel. Develop your understanding of how conditions affect burn rate so you can adjust plans on the fly. Plan conservatively, always, because a fuel stop you didn’t plan for is an inconvenience, but running dry offshore is a genuine emergency. That’s what makes fuel capacity planning endearing to us passagemakers — it’s the quiet math that makes ambitious voyages possible and keeps you from ever being that guy on channel 16 asking for help because the tanks went dry.