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Old 01-30-2019, 03:31 AM   #18
Fish53
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City: Rockport
Vessel Name: Ana
Join Date: Jul 2015
Posts: 1,047
Quote:
Originally Posted by Nomad Willy View Post
Comodave wrote;
“People often worry about the difference in fuel cost between the two types of hulls. Really if you run a SD hull ad displacement speeds the fuel cost isn’t much different”.

Not a realistic comparison at all in that a SD hull is quite happy running at hull speed ... maybe even it’s best speed to run. But running a FD hulled boat at it’s hull speed is insane. I think people have a notion that hull speed is the speed FD boats go. Far from it. Most run what their skippers feel is the best speed to run at that is very close to one whole knot BELOW hull speed. Wave making drag of a FD boat at it’s hull speed is extremely high. I’ll say only overpowered FD boats can even achieve their calculated hull speed. The overpowered boats would have over 4hp per ton of displacement. My boat has 5 and I question if I can actually achieve her hull speed of 7 knots.

So running at hull speed is world’s apart for SD and FD boats.

And Dave that’s what trawler forum guys talk about .. fuel consumption.
I'm obsessed with fuel consumption, I look with glee at the charts I get on Boatdiesel.com showing my boat doing .2 gallons per hour at 5kts, that's 25mpg in car talk. I don't yet know if I'll actually get that in practice but I like looking at it. Perhaps if I hadn't gone through those three wives I wouldn't need to pay so much attention.
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