Owner repower reports
What electric boats actually draw at a steady speed, measured by their owners — next to what the calculator predicts for the same boat at the same speed. Every published power-at-speed figure we've found so far is from a trawler; these are how the calculator gets tested on sailboats and launches.
Background: how accurate the calculator is against Nordhavn's figures.
Reports
“Calculator” is the configurator's shaft power for that boat and speed, divided by its default 90% drivetrain efficiency. A positive difference means the calculator asks for more than the boat used.
Add your boat
A good measurement takes ten minutes on a calm day:
- Pick a steady speed below hull speed — 4 to 6 knots on most sailboats — and hold it for at least a minute.
- Read the battery power on your battery monitor or BMS, or note battery voltage and current. That's what the calculator predicts — not the controller's rated power.
- Run both ways on the same course and average the speeds and powers, so tide and wind cancel out. Say in the notes if you did.
- Note the boat's condition: roughly how loaded, and when the bottom was last cleaned.
Reports are checked before they appear. We publish the boat, motor, measurements and the name you give (or “an owner”) — never your email. See the privacy notice; to have a report removed, use the privacy request form.