Egret Sharpie {Munroe} stability curve

[Lassuuu]

Can anyone help me please re the ultimate stability of an Egret Sharpie or its GZ curve? I believe from looking at MacNaughton's website that it might be unwise to take one of these offshore.

[balsaboatmodels]

Hey there Lassuuu;

While I cannot provide the stability curve, I can quote this from Reuel B. Parker's The Sharpie Book, p.160:
"Munroe designed the 28-foot double ended sharpie Egret specifically for running the shallow Florida inlets and handling the rough gulf Stream offshore waters in almost any weather. It was Egret that ran mail in all seasons on the east coast of Florida."

Sounds okay to go offshore with her to me.

Excellent book to have for one interested in sharpies.
Can be had from several places, got mine here:
http://www.woodenboatstore.com/
something which helps in ordering books is to know the book's ISBN number; this book is ISBN 0-07-158013-1

later,
FSW, on the banks of the Missouri River
favorite song: "Redneck Yacht Club"

[balsaboatmodels]

Tell ya what, gonna add another quote:
"I should explain further why Egret was a unique sharpie, and what aspects of Munroe's design enabled her to sail in the Gulf Stream during northers and run Florida's wild breaking inlets. Among her features that allowed such antics were her narrow, somewhat deep bottom, making her nearly a cross between a dory and a sharpie; her duck's stern, pointed and raised high to separate, and to lift to, following seas and breakers; and her short, gaff-rigged, cat-schooner sail plan. Hence she was deeper-bodied than other similar-sized sharpies and carried her ballast lower, making her self-righting; she could hardly be pooped, having no wide, low transom and deck to trap water like most sharpies had; . . . "

That's all I'm going to quote, copyrights and all, you know.
So, be good to Mr. Parker and buy his book.

Reuel Parker then explain how her sail plan helped her seaworthiness and follows up with this:
" Egret is widely acknowledged to be the most seaworthy sharpie designed and those are the reasons why. "

FSW

[Lassuuu]

Thank you Balsaboatmodels for your helpful comments. I have Ruel's book - it's great. My thoughts are in line with yours and I have a friend who took an Egret a considerable distance offshore. I guess I was wondering if anyone actually had any hard GZ data for Egret.

[melong]

Given that Egret is such a simple boat it should be fairly easy to work out the stability curve from scratch, as long as you have the scantlings and lines plan.

[Lassuuu]

Thanks melong,
Bit of an old retired duffer [60+] and not sure how to go about it, even though I have a set of plans.

[melong]

Ok, first up if you're going to build Egret as designed by Munroe you can forget about ultimate stability. She was basically an open boat with a cuddy, so as soon as water starts coming over the sides and filling the cockpit your stability curve becomes irrelevant in practice.
If you are going to fit a watertight cockpit and cabin then, at a guess (based on similar boats) Egret would run out of stability somewhere between 110 and 120 degrees. Don't quote me on that though if you're after an accurate figure.
If you really want to work out the actual stability curve I suggest trying to find a copy of a good design book via your local library network. "Skene's Elements of Yacht Design" is still good for the basics (despite being rather out of date) and Larsson and Eliasson's "Principles of Yacht Design" is a more up to date book.
Either one will show you how to do stability calcs. It isn't that difficult to get your head around but actually working it all out without a hydrostatics program is a little tedious.

[Lassuuu]

Thanks melong, this helps and will be sufficient for my purpose. 100+ degrees would be ok. I can live with that. My boat has a watertight cabin and self draining, small cockpit - in lieu of the original more open design. The cedar spars are also hollow and I've calculated about 100lbs [40+kg] of buoyancy for each. This will help quite a bit if she ends up horizontal. The cockpit seats and aft end of the coamings forming backrests also allow quick water shedding. And companionway entry sill is well above seat and deck level - even without the bottom boards in.
Regards Lassuuu

[melong]

Oh, so you already have the boat. How about a picture then?
Always did like the look of Egret. I first read about her in Wooden Boat.
A bloke in Florida had built a slightly modified version and was very happy with it.

[Lassuuu]

I think I've added a picture below melong - not terribly good at this sort of thing. If not, I posted a reply to dirtybeard [similar thread - assistance for his sharpie] which has a web link you can access. I've added a little 'dogbox' to give me 5'8" of headroom and rerigged the boat as a cutter [removed the foremast] - she sails better this way with a large staysail and yankee jib.
Regards Lassuuu

[Lassuuu]

Here's another melong - she's at home now for maintenance and a new paint job [Indian Red topsides]. Lassuuu