CONTINUOUSWAVE

Hi all. Give me input on a potential boat purchase on the boat's potential performance.

The boat s 2001 CONQUEST 26 (also known as 275 in later years) with 2005 Yamaha twin F225 engine. Would you anticipate this power to be sufficient for this hull under load?

Thank you for your input.

Some other observations
These boats were powered with OptMax 200 or 225-HP engine, but this one was re-powered. The boat is out of state and I cannot perform a sea trial.

I know about F225 exhaust corrosion; the exhausts have been replaced. I have also heard F225 engine really produce around 208-HP from what I've read.

The CONQUEST 26 hull is 6,200lbs, which is 2300-lbs less than the CONQUEST 28 (295) of the same era. The CONQUEST 28 also had hull design defects that the CONQUEST 26 does not, so experience with the CONQUEST 28 is not applicable.

[Performance] should be fine.

A rough estimate of top speed for a moderate V-hull planing hull is related to the power-to-weight ratio to the 0.5 exponent times a hull factor. This method of estimating was proposed by naval architect George Crouch. In his excellent book, PROPELLER HANDBOOK, author Dave Gerr mentions this method and demonstrates its use. To assess the boat under discussion I will use Crouch's method.

To estimate the weight I use the 6,200-lbs figure mentioned above.

For horsepower I use 416-HP, also a figure mentioned above.

For a hull factor I use 180. This value has been shown to be useful for predicting speed of the typical Boston Whaler moderate V-hull in prior calculations where the observed and estimated speeds were found to be in good agreement. This hull factor was developed by me based on Crouch's data which calculated boat speed in nautical-miles-per-hour rather than in miles-per-hour, and on test reports from many Boston Whaler boat hulls with known actual top speeds, weights, and engine power. If anything, this hull factor is a conservative estimate, as some Boston Whaler boats exhibit hull factors greater than 180, which would result in the estimated boat speed being corresponding greater.

These data then give a predicted top speed in MPH as

MPH = (416/6200)^0.5 × 180
MPH = 46.7-MPH

If the hull were 1,000-lbs heavier, then
MPH = (416/7200)^0.5 × 180
MPH = 43.3-MPH

As for the calculated top boat speeds meeting the criterion of "sufficient" I must leave that for the buyer to assess.

Additionally, proper engine set-up and propeller selection is important to ensure the boat performance is good at low-, mid-, and high-speed with a loaded boat in various sea states.