Florida Sharpie Length to beam ratio

[Florida_mariner]

Been considering another Sharpie hull project or even something a bit different and I was wondering if anybody had any input as to max beam...

I figure length will be between 16' and 18'...I want it to be very beamy for space and stability...

is there a ratio formula or is the width of allowable towing the only consideration? and pitfalls of being so wide at the beam?

TIA

Mike
Florida Mariner

[yipster]

not an answer to the question.
i just remember a 2 meter high cabin liveaboard sharpie building article.
they left the port side hull off till all interior was done, it was a pretty smart trick.

[Florida_mariner]

Thanks...I've seen a few like that this included...

http://www.duckworksmagazine.com/store/plans/markv/39/

I'd like to go way beamy...I'm just wondering how much is really practical in a 16'-18' hull...and how much would it effect the boats windage and other considerations...

[PAR]

Sharpie's typically were not to beamy, but 8' on a 18' waterline sounds pretty fat to me. This provides a 2.25:1 ratio and is going to cause a good bit of drag, unless you intend to be a planning craft.

With all things about boat design, everything must give some, in order to get anything. The space you'd like, provided by the additional beam, will be require more effort to propel. It also will give you additional initial stability (which you want), but will likely lower the capsize angle (which you may not want)

In the end, you will have to ask yourself some difficult questions, that only you can answer. Build a list of priorities - a "perfect world" list and a "can't live without" (bare bones) list. See what you really have to have and it's true importance to you. This will arm you with the final list of criteria, you desire in this boat, which is something a design can be built on. Personally, I start with general size, displacement and hull form and go from there. You've decided on the sharpie hull form, so that's one answer already. You have started the process. Continue with the lists and question/answer thing until you have refined you ideas and needs down to a firm concept. Then you can move on to the actual design stage.

[Florida_mariner]

sound advice...I appreciate it...this project I am contemplating would not be a sailboat...I already have three of those...I want this one to be a small cabin type boat...righting moment and heeling should not be much of a factor...I don't want to lose stability gained by add'l beam by going too high with a structure though...
I'm thinking about something kind of like a cross between conventional sharpie hull and trawler type hull...as for add'l drag I have a 9.9 kicker here to use...seems like it ought to push a 16'-18' boat of this type...
I didn't figure it would need to go across the water like an open class hydro :)
just as long as I can cover wind and currents and still make reasonable way I'm good...
just wanted a leisurely boat with a little reclining and fishing space and shallow draft and beaching capability...


any thoughts on ratio's of structure height vs beam?

[yipster]

see my last post at http://www.boatdesign.net/forums/showthread.php?t=1592&page=2&highlight=cb with some simulators.
you see the cg playing the major role, not height or beam and you can even put waves on your design for stability, get a feel :D

[Florida_mariner]

that is handy...I appreciate you passing that on...I'm gonna have to take some time to figure it out :)