GPH vs GPM vs MPH

Mr Efficiency
Thanks for the link on this boat
As a contributor stated, this looks like a hull that one would be matched with a low HP engine and corresponding slow speeds but the aft chine lines are relatively parallel to the keel, not skeg, they are not rounded to get some pressure recovery like a displacement hull and the transom is say square to the keel. So it looks like and can act as a planing hull.
The skew is the problem and the idea of narrowing it is spot on
In the other thread, it was suggested that the flat at the back of the skeg imparts more drag than the flat at the front. Not so. Taper the front first. The back of the skew which is flat will introduce turbulence over the prop blades. A thinner skeg that the builder is suggesting will reduce both leading edge impingement drag and trailing edge low pressure drag.

If you are considering building a plastic bushing, ensure that the id of the bushing has a few longitudinal sipes to allow water to get down the bearing. A smooth id will wear out quickly

 

I spent a couple minutes looking around:no Bluewaters get better mpg as they go faster.

Just to show it can be done,my boat is 50',twin 640 Cummins and at 14 knots I have a range of 215 nm yet at 24.5 knots it's 250 nm.

The Silverton 45 is interesting: twin 430 Cummins and at 10.3 knots it has a range of 250 nm, yet at 14.5 knots she's popped up on plane and tuned to cruise there as the range is 320 nm.

At 24.5 knots I have the same range as the Silverton does at 10 knots, as we both carry 500 US gallons,and at lower speeds I get quite a bit better mpg.

 

Thanks, thats the sort of info I was hoping for. My boat isnt as big, or as well designed but I don't see the need to spend money to pay for fuel just to drag around a skeg/keel. Even if I dont gain speed, not having that keel to drag around should make the mpg better.

 

Sometimes the answer to a problem is so obvious nobody thinks of it. You want better economy lighten your boat. Many boats get their best performance fresh from the factory before the new owner piles them full of gear and junk. For a little test, run your boat with full tanks and measure fuel burn and speed, then do it with almost empty tanks.