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On 03 Jun 2004 16:12:17 GMT, (Gould 0738) wrote:
A boat with the operating characteristics NOYB described would be frustrating
as hell. A difference of 500 RPM increases the speed by 2 1/2 times? Unless you
wanted to run (and the conditions permitted) 25mph, you'd have a dickens of a
time setting the throttle for a speed somewhere between 9mph and 25mph and
keeping the boat there.

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Actually, that's just about how my 5,000 lb, 24 ft I/O performs. From
1000 RPM up to 2500 the boat is just pushing water and making waves.
Speed climbs from around 5.5 kts to about 8. Starting at 2500 the
boat will come up on a slow, labored plane at about 15 kts which is
useful only for running in a nasty chop with the bow up. Starting at
2800 it comes up onto a semi-comfortable plane with a speed of 18 to
19 kts which can be sustained with minor throttle tweaking. At 3000
RPM and 20 kts the bow comes down, the boat trims out nicely, and it
gains about 1 knot for every 100 RPM thereafter. Anything under 3000
RPM is not really fun for very long.

Obviously these characteristics vary a great deal depending on the
length and weight of the boat, and the type of motor.. My 12 foot
inflatable for example will come up onto a nice stable plane at about
12 knots because of its light weight and short length.