GT 23 hull questions

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fallguy1000
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Re: GT 23 hull questions

Post by fallguy1000 »

jbo_c wrote: Sun Aug 01, 2021 9:05 am As seen on another thread, I’m considering taking over an incomplete GT23 project. That hull is not really what I was looking for originally, but it is tempting. So I have a few questions - mostly for Jacques, I guess.

1. The “houseboat” hull: According to the study plans, the difference is in the forward volume and the transoms are the same. So the houseboat hull is also what we’d refer to as a “planing hull”? Or maybe as a whole, the design is more semi-planing?

2. Along those same lines, Jacques notes that a 25hp would be perfect. That still confuses me if the hull is a planing hull. How is that? Is this statement true for both versions of the hull?

3. This one may be harder to answer. My intent was to have the cabin more aft. Since this is the ‘performance’ hull, I’m thinking my aft cabin would actually be the better way to do it anyway. Is that right? How do I make sure the weight distribution is “correct”? Looks like my I intended cabin will be lighter(smaller) than what’s on the plans, but probably not a lot as I really don’t have any plans to make it out of foam.

One of my biggest ‘concerns’ is that my intent has always been for very low power - 10hp or less. Don’t want to invest a lot of time and money in this only to wish I’d stuck with my original thoughts. (I know I’m the only one that can make that call.

Jbo
More aft...

Be careful, this is a generally incorrect concept.

Most boats with outboards need centers of mass aft of the midline, but an open bow, aft cabin boat may perform poorly. Ask the designer.
My boat build is here -------->

viewtopic.php?f=12&t=62495

jbo_c
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Re: GT 23 hull questions

Post by jbo_c »

I agree, FallGuy, but as Dougster noted, it’s been said in the past that this design may tend a little down in the bow. That’s why I thought the aft cabin might work. We’ll see what Jacques says.

There’s also that recommendation of 25hp in the study guide, so Jacques also is saying that this boat in general is better off at displacement speeds.

Jbo

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Re: GT 23 hull questions

Post by BB Sig »

I don't think Jacques was the original designer. He did fix it though... 😄

The weight moved after has been proven to fix the nose down at rest and has not been detrimental when done within reason. I don't believe that anyone would add lead to a reverse a fix.

The bigger deal to me is the original poster doesn't like the design. If you aren't sold on the issues I would not want you to take it. I want this to go to someone who wants to finish it, not feel the must because they got stuck. 👍

edited to add: Don't take this as a slight. It's more of me reading what your posting. I think it's a great deal but only if you want it... :D

GT 23 Bow Down Discussion

More GT 23 Discussion

Good GT23 Info from"Daddy"


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Last edited by BB Sig on Sun Aug 01, 2021 10:53 pm, edited 3 times in total.

TomW1
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Re: GT 23 hull questions

Post by TomW1 »

jbo this is a planing boat all Jacques is saying is that a 25HP can be used for displacement speeds it is not the preferred motor. He describes what motors for planing speeds to use in the write up. The 150HP will push her to a top speed of 35mph or more depending on load.

So wait on Jacques on moving the cabin back.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

jbo_c
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Re: GT 23 hull questions

Post by jbo_c »

Good info in those old posts. Those are some of the discussions I remember.

So according to Jacques, the new version of the hull can be fit with bigger engines for planing, but is designed for 25hp.

Jbo

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Re: GT 23 hull questions

Post by TomW1 »

jbo_c wrote: Mon Aug 02, 2021 6:32 am Good info in those old posts. Those are some of the discussions I remember.

So according to Jacques, the new version of the hull can be fit with bigger engines for planing, but is designed for 25hp.

Jbo
So get it and finish it to your liking and enjoy it you will have a great boat the rest of your life. :D The price sure is right.
l
Good luck what ever you decide.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

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Re: GT 23 hull questions

Post by jbo_c »

Reading through those old posts this morning solidified that this hull really won’t fit my plan. Guess given the ‘price’ I was trying to show-horn it into working for me.

Hurts, but I’m going to pass on this hull and press on with my original build intention.

Thanks for the feedback everybody and especially to BB who seems to be a standup guy offering a great deal for the person that hull fits.

Jbo

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