Jones Brothers Marine boats are almost legendary in their seaworthiness. Courtesy Jones Brothers Marine.
Our post on estimating how much horsepower you need to cruise at a given speed made use of a rule-of-thumb we found in a couple of different books. So how accurate is this rule-of-thumb?
Here are some examples from published test results (only monohulls with single motors were considered).
If you want to check out your own test results, try our Boat Horsepower Calculator. It’s a handy tool for estimating your boat’s total weight, and uses hull deadrise and the rule-of-thumb to estimate the horsepower needed to run at a certain speed with 75% throttle.
| Source | Boat | Weight as Tested (est) | Horsepower Tested | Predicted HP for 25 MPH | Actual Speed at 75% max RPM | Predicted Speed (adjusted for HP diff) |
| Powerboat Reports January 2001 |
Edgewater 225 CC | 4,400 lbs | 250 | 176 | 37 mph | 36 mph |
| Powerboat Reports January 2003 |
Seacraft 23 CC | 5,000 lbs | 225 | 200 | 30 mph | 28 mph |
| Powerboat Reports March 2003 |
Pacific Skiff V2600 | 4,500 | 225 | 180 | 31 mph | 31 mph |
| Powerboat Reports October 2003 |
Mako 212 CC | 4,500 | 225 | 180 | 33 mph | 31 mph |
| Evinrude ETEC Performance Report | Aquasport 175 Osprey | 2,600 | 90 | 86 | 29 mph | 27 mph |
| Evinrude ETEC
Performance Report |
Sea Boss 190 Bay | 2,180 | 90 | 73 | 26 mph | 33 mph |
| Powerboat Reports November 2003 |
Sailfish 234 | 5,500 lbs | 225 | 220 | 27 mph | 26 mph |
| Powerboat Reports December 2003 |
Wellcraft 252 Coastal | 5,800 lbs | 250 | 232 | 34 mph | 27 mph |
| Powerboat Reports January 2004 |
Polar 2100 CC | 4,100 | 200 | 164 | 32 mph | 30 mph |
| Boating July 2004 |
Triumph 191FS | 2.700 lbs | 115 | 91 | 31 mph | 32 mph |
| Trailer Boats August 2004 |
Hydra-sports 2300 Bay Bolt | 4900 | 200 | 163 | 33 mph | 31 mph |
| Trailer Boats September 2004 |
Triton 170 cc | 1,700 | 90 | mph | 57 mph | 39 mph |