Welcome (as a “human being”) !
A 30’ boat can have many shapes, depending on intended use on inland/coastal waters.
Displacement and hullshape determines the fuel consumption/hour.
Speed determines the power demand exponentially much more pronounced than on land.
The wood volume loaded on board gives more miles for a displacement boat than a half-planing one.
A 30’ displacement boat with a smooth hull makes ~10 kn with 15 - 30 hp…
150 hp talks about planing or half-planing ambitions, which does not give many hours long trips.