Interactive chart
Same speed. Fewer revs. Drag the line.
The story every Autoprop owner tells — 2,500 rpm down to 2,100 at the same six knots — as an interactive chart. Set your engine and waterline, then drag the cruise-speed line.
Curves are indicative, modelled from documented fitments and the independent-test pattern. Hull speed follows from waterline length; the Autoprop curve reflects the typical 300–400 rpm reduction at cruise.
Run my actual boatFixed 3-bladeAutoprop
Data table & assumptions
| Engine RPM | Fixed prop (kn) | Autoprop (kn) |
|---|---|---|
| 1000 | 2.9 | 3.3 |
| 1500 | 4.1 | 4.6 |
| 2000 | 5.2 | 5.9 |
| 2500 | 6.3 | 7.1 |
| 3000 | 7.3 | 7.7 |
Indicative curves modelled from documented fitments and the pattern reported in independent testing (6 kn at ~2,100 rpm with Autoprop vs ~2,500 rpm with a standard fixed propeller). Assumes a displacement hull of ~10.5 m waterline; your boat's real numbers are confirmed by a Bruntons engineer before we supply anything.