What floats your boat.

"On the contrary, assuming constant mass, max beam, LWL, etc it isn't possible for a V bottom to not have a deeper draft"

Yes, you are adding constraints, then making a conclusion WITH the added constraints in place. That is the point of the last paragragh of my post. HOWEVER, the constraints you mention indeed do not necessarily result in the v type hull having the deeper draft!

Think about that while I make a couple of drawings illustrating this.

 

Also needed are constraints on same waterplane shape and area, and same flare of sides.

 

Yes they most certainly do result in the V having deeper draft!

I'm eagerly looking forward to your drawings

EDIT: You're right if talking about two different vessels. But we're talking about two vessels where one is a flat bottomed hull designed to have as shallow a draft as possible, and where the only difference between the two is the bottom.

No, constant max beam (not waterline beam), LWL already takes care of this (from a flat bottom to an added V bottom). The flat bottom boat will necessarily have the maximum possible water plane.

 

A V-bottom with same max beam and LWL but larger waterplane area and/or less side flare may have less beam than a flat bottom boat.

 

Why will the flat bottom boat have the maximum possible water plane area?

 

The flat bottom WP area will be the bounding box that the V bottom WP must sit inside. It's the maximum of what is possible for the V hull.

 

What do you mean by this? Speak clearly please!

 

Less beam will also mean deeper draft, so that fits just fine.

You're right though, I've been assuming no tumblehome for the flat bottom vessel.

But if you think you can draw something that shows me to be wrong, please do! (Adding a V to an existing flat bottom vessel)

I'll wait for as long as it takes

 

Same Displacement, Same LWL, Same BWL

Adding the constraints of same Displacement, Same Length on Waterline, and Same Beam on Waterline, one can imagine a hull with a flat bottom having greater draft than the Vee type hull.

Add some more constraints?

 

Hah, yes well done, there are more constraints: do it by adding a V to an existing flat bottom vessel. It needs to be same vessel, where the only difference is the bottom, as per the other thread where Tom started this discussion.

 

By "waterplane area" I mean the area of the surface bounded by the waterline. What do you mean? Why would the V bottom waterplane have to fit inside the flat bottom waterplane?

 

I'm referring to the outline of the WP. But the area will be less or equal for the V too.

It WILL fit inside the flat bottom WP (adding a V to an existing flat bottom, const mass, no tumblehome).

 

OK, Looking at my rocking chair.....

Yet another constraint is needed?

 

Yes, use a realistic flat bottom vessel.

The flat hull we're talking about is one that has been designed to have as shallow a draft as possible - not at all like your mutation.

Please don't just jump into the end of a thread without reading its history - read this first: http://www.boatdesign.net/forums/boat-design/false-bottom-v-flat-bottom-53189.html
The situation under discussion has been predefined, those of us who've been here since the start are aware of it, you aren't.

In other words, do it in section, while ignoring the third dimension.

 

Fundamentals

OK, my posts here were only intended to illustrate that the fundamental equations are perfectly valid.

In this thread many were making conclusions without actually considering the unwritten constraints that they were including into their mind's thinking, but not the written words of their posts.

My sketches show exagerated features to illustrate that these additional constraints must be included if one is making statements as if they are absolute truth.

Yes, with two vessels generally the same, then the Vee bottom will generally draw more water, but that word "generally" is needed for the statement to be correct. I read all the posts here, that is what prompted me to respond, being a teacher of engineering courses, although usually where the liquids are inside pipes.