How well do you guys think this tunnel hull will go through the water?

BigB9000

Lieutenant Junior Grade
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Dec 5, 2007
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1,154
Im hoping better than my flat bottom, thats why Im going to buy it:

pregl-carlson-66cat-pg4.JPG


opinions?

the tunnel dosnt go all the way back, it becomes flat on the back 1.5 feet
 

reelfishin

Captain
Joined
Mar 19, 2007
Messages
3,050
Re: How well do you guys think this tunnel hull will go through the water?

I would probably expect a pretty rough ride from that, sort of like a trihull gives in choppy water. The hull design would probably make it turn like it's on rails though.

I think the partial tunnel in the front will 'trap' water create a slapping effect.

It's a cool looking hull though, how much power will you hang on it?
 

BigB9000

Lieutenant Junior Grade
Joined
Dec 5, 2007
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1,154
Re: How well do you guys think this tunnel hull will go through the water?

Max says 110.

Ill put my 81 Johnson 115 on it
 

BigB9000

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Re: How well do you guys think this tunnel hull will go through the water?

anybody?
 

mrdancer

Petty Officer 1st Class
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Aug 21, 2008
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Re: How well do you guys think this tunnel hull will go through the water?

A flat bottom is the most efficient, fastest planing hull available. It also has the shallowest STATIC draft. For a more efficient hull, you would have to go to a canoe or kayak, which typically aren't considered as planing craft.

The only reason to go away from a flat bottom is to increase ride comfort, and possibly increase boat control at higher speeds (>40 knots). A true flat bottom can provide a rough ride in anything other than glass-smooth water, particularly if it is a lighter boat.

A hull with a pocket tunnel will allow the boat to run in shallower water (dynamic draft), but it will not float in shallower water (static draft) than a true flat bottom hull.

A boat with a true tunnel will have a relatively deep static draft, but will be fast and shallow-drafting at speed.

Catamaran-type hulls could be considered an extreme form of tunnel hull, but are actually two separate hulls. They are known for their soft ride.

I wasn't able to see the picture of your boat, but it sounds like a type of a Hickman Sled hull form - it will have a slightly better ride and maybe draft a little less at higher speeds than your flat bottom. As another poster mentioned, you will probably experience hull slap and possibly burping (water spraying out from under the bow). I doubt you would see higher speeds with the same motor configuration, assuming all else is equal, etc.

V-hulls are the most common hull forms because they are generally comfortable and relatively safer in rougher waters. They do, however, draft more water than a flat bottom and aren't as efficient.
 

NSBCraig

Lieutenant Commander
Joined
Aug 21, 2007
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1,907
Re: How well do you guys think this tunnel hull will go through the water?

Post it on the scream and fly .com forum there are a lot of tunnel boat guys on there that can give you good advice.

That's where the speed guys are, this is more for old pleasure boats.

The post above is a good example. I know he is trying to help but the info makes no sense a v bottom speed boat rides on a pad on the back of the hull. Roughly two foot by one foot of boat is all that is in the water with a hull draft of about four inches at the most. The only thing really in the water is the bottom of the motor. When planing the are way more efficient then a flat hull, the flat hull is contacting the water more meaning more resistance.
 

mrdancer

Petty Officer 1st Class
Joined
Aug 21, 2008
Messages
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Re: How well do you guys think this tunnel hull will go through the water?

The post above is a good example. I know he is trying to help but the info makes no sense a v bottom speed boat rides on a pad on the back of the hull. Roughly two foot by one foot of boat is all that is in the water with a hull draft of about four inches at the most. The only thing really in the water is the bottom of the motor. When planing the are way more efficient then a flat hull, the flat hull is contacting the water more meaning more resistance.

My bad... with high horsepower and light weight, the speed boat is more efficient at high speeds. However, it will take several magnitudes more horsepower to get it up on plane as compared to the flat bottom...
 

NSBCraig

Lieutenant Commander
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Re: How well do you guys think this tunnel hull will go through the water?

Yeah them flat bottoms are pretty much on plane already.
 
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