On Thu, 22 Nov 2007 08:55:50 +0700, Bruce in Bangkok
wrote:

The Grand Banks hulls are semi-displacement hulls and probably produce
an optimum distance/fuel consumption at higher speeds so just puling
the throttles back will probably not accomplish a really major
increase in fuel economy.

Depends on what you call major.

By cutting back 15 % from maximum cruising speed to "normal", fuel
economy doubles as horsepower is cut in half.

Reducing speed another 20% below normal gives an additional 50%
improvement in NMPG.

GB42s can be made to plane if sufficient power is applied but that is
nearly impossible with our GB49, even with close to 600 hp available.