High LW ratio planing hull

[Hotel Lima]

Does anyone know how stable a high LW ratio planing hull is? Does anyone have any information on how to design a hull like this? Talking 8:1 or so.

[Guest625101138]

Stability will be a function of beam mostly. If it has a 20ft beam and is 160ft long it will take more than your weight to roll it around.

Rick W.

[tom28571]

Originally Posted by Rick Willoughby

Stability will be a function of beam mostly. If it has a 20ft beam and is 160ft long it will take more than your weight to roll it around.
Rick W.

True enough, but that is not the whole story. A 8:1 L/B ratio is going to be rolly unless there are some heroic measures taken to prevent the rolls. Think of a 40' LWL boat at 5' beam. Such a L/B ratio is iffy in a displacement boat but for a planing boat, the stability would be worse.

For displacement boats, long and slim has always proven to be faster. For Planing boats, it's just the opposite, with short and beamy winning out. In both cases, going too far creates problems of stability. The evolution in boat design would get nowhere unless some are willing to step outside the box and push things a bit. On the other hand, you don't want to be the mutant disaster that proves something should not be done.

What is the need that brings up the 8:1 prospect for a planing boat?

[Hotel Lima]

For historic aesthetics. It's going to need to accommodate a fantail like this vessel.

[Chris Ostlind]

WTF is in that thing (Engine-wise) that would ever give you the notion that it can plane?

There are double enders that can plane (Bartender skiffs) but, "I know Bartenders and HL, this is no Bartender." (All apologies to Lloyd Bentsen)

It's a power to weight to planing surface thing, HL and unless you are sporting a UH-1H turbine engine in that thing... forget it.

That's a full-on displacement hull in what one would consider a "normal operating" mode. Get an efficient engine, a good prop solution and enjoy the cruise.

[tom28571]

Originally Posted by Chris Ostlind

WTF is in that thing (Engine-wise) that would ever give you the notion that it can plane?

There are double enders that can plane (Bartender skiffs) but, "I know Bartenders and HL, this is no Bartender." (All apologies to Lloyd Bentsen)

It's a power to weight to planing surface thing, HL and unless you are sporting a UH-1H turbine engine in that thing... forget it.

That's a full-on displacement hull in what one would consider a "normal operating" mode. Get an efficient engine, a good prop solution and enjoy the cruise.

Hi Chris,

All he needs are a couple big pickle fork sponsons, a couple real large Bartender aft wings and a J57 in the stern.