Yes, many boats are underpowered. However, if the target speed is reduced to about 75% of
hull speed ( a ratio of 1.05 instead of 1.34) the HP required goes down to 1HP per 1000
pounds. This is why any sailboats are slower under power than under sail. (OK, there
are a few other factors ...)

A "True Motorsailer" will have more like 1 HP per 250 pounds - enough to keep the speed up
in adverse conditions. Two examples are the NorthEast 400 (100 HP for 22000 pounds) and
its big brother Bruckman 480 (140 HP for 42000 pounds)

-jeff

"Bobsprit" wrote in message
...
The rough rule of thumb is that one HP for each 500-600 pounds
of displacement is required to push a boat to hull speed.

Does this take into account adverse elements, such as wind and current or it
just for flat calm water? Seems to me that many boats are way underpowered
based on the above.

RB