The fuel flow test results shown in boating mags shows that with many boats,
Eisboch is correct. .

About what?

About a properly trimmed boat getting better fuel economy once on plane and at
a given throttle setting? Yes, indeed.

About the easy misread of his post implying that boats get progressivley better
fuel economy at higher RPM's, once properly trimmed and on plane? I don't think
that's what Eisboch meant.

There is a period of time when the boat is technically over the bow wave and
could be said to be "planing" where there is still more resistance than there
will be when the boat achieves optimum plane. In this window, the "giving it
more throttle improves the fuel economy" model might apply......but the boat
hasn't actually met the condition of being truly on plane during that period.