Narrow beam and flat bottom...compromises

Is this a Munroe Egret type? Image on pin-interest.

 

Not so narrow......but shallow. Homebuilt plywood skipjack.



36ft x 10 but 2ft draft.



A better shape than and out and out "box", but with still the same load carrying as the sharpie types.

 

A Skillygalee? Looks like it.

 

It is if it is 28 feet. See this designers blog for the original lines and a smaller open copy.
Ross Lillistone Wooden Boats: "Little Egret" - an Egret-style Sharpie https://rosslillistonewoodenboat.blogspot.com/2011/10/little-egret-egret-style-sharpie.html

Edit: Wooden Boat sells plans of EGRET
28' Sharpie EGRET | Wooden Boat https://www.woodenboat.com/boat-plans-kits/28-sharpie-egret

 

A modified Bolger Martha Jane. Usually 23ft x 6ft with 7inches draft. Looks like the stem has been changed too. Apparently had a hardwood bottom job done to improve self righting. No leeboards either.

 

Flat-bottomed sharpies are the optimal solution when your empty weight outbound is 1/8th of your return weight. Otherwise, like for anything other than oystering, they aren't the best. Even in stupid skinny water they aren't the best. Nothing, and I mean nothing, gets stuck in the mud like a flat bottomed boat.

The skipjack type is far better when you have some clue about your displacement - like it only varies by 50%, not a factor of 8. These are often called file-bottomed sharpies. There are also Rosyln-types (see Chapman) that have an arc bottom. For skinny water use (I sailed the Florida bay out of Flamingo and Key Largo for many years) I'd go with a 7 degree deadrise midship for trailer sailors. The sides should flare 13-15 degrees midship (the higher number for very low sides, 13 is fine if you have 30 degrees of heel and no water coming in at full load. This gets you several things.

If you drive into the mud, you can get out and tilt the boat and lessen the draft a fraction of an inch, letting you push off.

On the trailer, rainwater runs to the center and out the drain hole. I doesn't get trapped in corners like on a flattie.

It sits on the trailer well with center bunks and side bunks. The gradual flattening of the deadrise lets you sail onto the trailer even when it is quite flat. A flat, rockerred bottom can be difficult to get on and off the trailer in these conditions if you can't sink the backs of the bunks, although tilt trailers work for smaller craft.

Correctly designed, the file bottom has less wetted surface when sailing, and will often get you a bigger boat using 4' wide panels. On trailerable boats, they will put on maybe 2 degrees more heel going to windward - say 12 degrees instead of 10 for a flattie.

As far as bows are concerned, once dragging the thing up a beach beyond the surf line is out of the question, putting a chin on the bow is probably better than a spoon bow. The next point of concern is crashing into/dropping off the end of the trailer's center bunk. But if you don't carry 200' of painter to winch your boat back to the trailer, maybe not an issue. Morejohn's boats weren't designed around trailer sailing in skinny water, they were built so that they could. Burying the bow will make life much more pleasant aboard when anchored. But for trailer boats with only occasional overnighting, and generally not carrying a dink (maybe towing one), keep it nearish the waterline. You want to be able to sneak up 0n the shore, step off, and stuff a cushion under the bow for a bit while you look around and pee the dog. For that purpose I like a dead straight keel line running up to a tight chin that's just below the waterline. The cushion stays put better.

That Egret belonged to Biscayne National Park when I was down there. I crawled around on it but never had the chance to sail her. IIRC, it was built by one of the park rangers. Of all the recently built *Egrets*, she is the closest to Munroe's original. Nearly all the others have raised sides and higher cabin tops.

 

All good info Phil, thanks.
The load carrying is of interest but 8x is not required. With regards to Egret and similar, Bolger is said to have sailed one, and his Blackskimmer design would sail rings around it, and that Skillygalee is based on a stretched Blackskimmer.
Im thinking skinny but long waterline, rather than short and fat for the same displacement, shallow because i may have access to almost free storage in a creek, rather than in a marina, simple and basic because an unattended boat will draw less attention.
I have also been down the "box-keel" wormhole and i have been sold on the advantages.
I found the lines and offsets for a skipjack that appears close to your V bottom and flare sides.



There is a drawing of it with a rig also. (forget that large house) This would certainly power to weather far better than anything else without pounding, and even without a box keel, the engine/shaft angle is the same as i have worked with prior in a boxkeel design. Much as i like the Skillygalee, either bringing the bow down or adding a V forward would be required if motoring for any length of time into chop . I think realistically the same could be said for the flattish but narrow entry Atkin boats too.
I have a lot of drafting to do........and possibly some test models.

 

Wow, that's interesting and has given me some good googling to do. Thank you

 

So Skaraborgare, wat's your SOR?

 

Its a hypothetical at the moment, but the needs are real.

Imagine a free berth for a shallow draft boat, that means a self imposed limit of 8m can be extended for 10m as times spent in a marina would be minimal, and the extra waterline length will pay dividends under sail and motor.
It must be able to sail, at the very least away from any immediate danger. I want a rig in a tabernacle, and i do not need anything bigger than the rig on a Marth Jane, a balanced lug main with a sprit mizzen.
The contentious part is part is the minimum requirement for 200 litres 52 gall (us) of diesel, for motoring through the Azores high. This vessel will only ever be required to get from Brittany France/ Lisbon Portugal out to the Azores islands, during the summer season. Call it a travel boat, not a live-aboard. It will spend more than half its time in a mud berth under a canvas cover spread over its lowered mast, devoid of any interior fixings bar the small diesel engine and a fuel tank.
So far im thinking the 5000lb Skillygaleeis enough, im just working on giving it a shallow V body with a sharp entry, rather than the flat bottom. 18-24in draft is ideal, a ballasted daggerboard can be deployed when required.

Im aware i could always buy an Albin 25 and put an aft extension on, just for some more waterline, but that would involve a lot of glass grinding, and wheres the fun in that?.

 

....fully appreciate that point, good luck!

 

Beautiful.. Was it yours? How was it ballasted?

 

No, just a find from browsing. Heres the page with some more info.

Duckworks - Skipjack "Messenger" (duckworksmagazine.com)

There are plans for a 24ft version 24' 8" Skipjack, CALICO JACK | Wooden Boat

 

Great article, thanks!

I know about Calico Jack, just bought Boat Design Quarteerly No.12 yesterday to read more about it.

There is also nice little 20ft skipjack by Selway-fisher.

 

So, I have returned to the box keel concept, for least draft for a given displacement, and with more V than my last project. I dont have the eye sight to count off little squares to figure displacement, so i fumbled around in the shed for a bit. Just needs skinning.



4 sheets of ply long and 6ft 6in beam. I usually work in one and a half inch to the foot, but in this case it was one inch to one foot. Problem is i forget the sum for figuering model to real weight. I know the other scale was times 316 if i recall.
I think just by looking, i will have more capacity than i need, i could probably reduce the deadrise down to 10-12 degrees, if its excessive.