What floats your boat.

A V bottom boat of a given weight and a constant width has a larger draft than a flat bottom hull

Assume that the boat has a chine width of 8 feet wide and is 20 feet long and weighs
5000 pounds.

Ignore the diminishing displacement of the bow taper as right now we are only "floating the boat"

Each lineal foot of the hull weighs 250 pounds and therefore has to displace 250 pounds of water or 4 cubic feet per lineal foot

Assume, just to make things simple, that the waterline and the chine width is the same

The draft of a flat bottom boat will be 6 inches, the draft of the V bottom boat will be
12 inches. The deadrise will be 14 degrees.

Remember, the chine width and the water line are the same.

 

Nope, it's everywhere. You're just not looking in the right places.

To save you those millions...here is an excerpt from basic ship theory on this very subject. Now you can lift the vail of ignorance....for free



Not happy with those, try this one too:

 

I prefer simple Boats... My canoe is very simple. Once I out too many things to make a nice design to my small canoe, but I failed. now I painted it. I prefer paint instead of some materials to be put on boats.

 

That's true, but we were discussing a known (to us) situation. The large majority of posts were directed specifically at Tom, who of course was aware of the details of what was under discussion better than anyone.

It wasn't intended for publication or public consumption, and writing all constraints and assumptions into every post of a web forum is completely unrealistic.

So to reiterate, for Tom: you cannot have a V bottom with the same draft as a flat bottom in your situation. The V will always have a greater draft.

 

Here's the essence of this thread...If my aunt had balls, she'd be my uncle and if he had ham, he could make a ham and cheese sandwich if he had cheese.

As a teaching experience, it hasn't taught me anything about buoyancy, but a lot of other thoughts have popped to the surface, so to speak.

 

to me this thread proves that even a grown man can be an obnoxious internet troll. And that many of us are vulnerable to such behavior. thanks ad hoc for those attached images.

 

More compressed area generates more lift, up to:

http://www.lilienthal-museum.de/olma/images/teppich.jpg

pogo


P. S.
Americans !!!

 

I am getting saturated and dizzy with the with pros and cons and finding it difficult to keep up. But all good posts.
We have requirements for a boat for a customer at post #6.
I can not see that mass has as yet been set, just a wish list.
Luckily the customer who knows what is going on has not phoned to cancel his request and financial support.

Is anyone going to recommend which shape should be used to satisfy the customer needs for this project?
And is it possible to completely clear up which shape will fit our project best.
Nice to have a very patient lot of friends.
I have my horrible mal ware hijacker back again and need lot more broardband data.

 

The SOR in post 6 is not specific enough to choose one exact shape.

Start by having your customer list specific requirements.

For example:

draft must be no more than (_) inches at rest and (_) inches running carrying
(_) persons and (_) lbs gear, fuel, water, and other equipment.

must run at (_) mph; must be comfortable ride in (_) foot waves at (_) speed

beam constricted to (_) feet or maximum road trailer width?

Start with a comprehensive list of requirements which must be met.

For some reason your customer has chosen an image of an older flat bottom as a starting point. What made them choose this image? Do you absolutely have to incorporate any elements from that to satisfy your customer?

Then you can ascertain whether it is possible for you to design a boat which achieves all the customer requirements by working on a design (or having a NA work on a design) and calculating weights to achieve required strength and the subsequent draft.

One of your premises is that a shallow v bottom can be lighter than a flat bottom. This is true under certain circumstances. It depends on all the other requirements and how each is designed. There is not enough fixed by your SOR in post 6 to have only one solution. (All flat bottoms don't require a "deep keel" or "bad rocker" which you described as bad attributes of flat bottoms in post 102.)

If you have a real client and you already know you want to design a shallow v for handling and beach hauling, start designing a boat or hand over the SOR to a naval architect and have them get to work, evaluate, and revise to meet the SOR. If you can meet the draft requirement and have other favorable attributes, this is your answer. If you cannot, then you revise to meet the SOR and if necessary prioritize the elements of the SOR.

 

How is the "customer" going, is he satisfied yet ? The "customer" is always right, they say, but this time could be an exception !

 

We will discuss progress when we have good stocks of information for our project.

Venture capital is a rare thing and not to be wasted.

As one post suggests I could hand this project to a NA and I have been checking around at their work. there is some interesting work around.
But look at the plane angle, that would not be shallow draft but is a lot bigger than our customer needs.

 

Thank`s for that and more customer requirements can be added to that list.
I will print out use it as a guide and add it to what already we have.

 

I think I should think about putting someone on my ignore list.

 

Thank`s I have had a quick look but will follow up on that info.
But how can we be certain it is the good "oil" or doubtful in some ares
like some say teachengineering.org. is misleading.

 

Something fishy going on here? You already introduced your favorite DN Goodchild boat Lily Pad redesigned as a v bottom boat with no keel just a metal rub strip. in a previous thread of yours. Are you the customer? http://www.boatdesign.net/forums/boat-design/quick-easy-build-you-go-shallow-draught-50791.html