how about a 25hp outboard on a planing sailing dingy?

thx, PAR, so what is your best recommendation hull starting point

for the type of boat/usage I've described in the 20'+ or - range?

1)Good sail boat(not a racer) with simple rig(and use of sail for sun/rain cover).

2)Able to work well with outboard.

3)Fairly wide range of load, from single person to 1000lbs cargo.

4)Not a Epic Bad Weather boat, mostly exploring bays, rivers and lakes....and of course easily trailer-able. Minimal cuddy cabin.

5)Row-able, or even canoe paddle-able(with lots of crew).

I'm thinking of a shape like Grumman Sport Boat, but puffed up to 21', and done in Cold Molded epoxy wood strips or multi-chine stitch and glue.

http://www.sunshine-sports.com/store/8164




$0.00 S/HGrumman Sport Boat shown with optional Olive Drab paint.

Standard Features:Increased width, high bow and splash rails not to mention it is built like a tank are the attributes that make this boat the #1 choice of fishermen and hunters.
Proven Safety Features: More rivets than other aluminum canoes, large flotation, and sturdy transom.
This product must ship by motor freight. Shipping fees are not included in your order. Please call for a quote.
Click Here For Sport Boat Reviews

 

Gig harbor boats in WA. makes a copy of a 1930s lobster sailing rowing power boat that with 10-15 Hp OB fills the bill Google there site. This boat was developed to fill the 20MPH power+sailing and rowing ability.

 

thanks, eyschulman, that 15' Lobster boat is about exactly

what I was after, except I was thinking of something a little bigger(longer) but it looks like that 15' size would be more realistic 95% of the time.

$6000+ for rowing and $10,000+ for sailing versions.

I'd like to see the boat in stitch&glue or cold-mold strip plans, and maybe some use of modern building practices to reduce the weight a little (and reduce COST alot), and a few features I mentioned like:

combo spud-pole/dagger-board,

combo sails&mast/sun&rain cover(have a mast that hinges, and works with the boom, to become a support for quickly deploy-able large cover big enough to keep rain out the entire cockpit),
I'M NUTS FOR ANYTHING THAT 'TRANSFORMS' AND DOES TWO COMPLETELY DIFFERENT TASKS WITHOUT ANY SIGNIFICANT COMPROMISES

sliding seat rowing,

micro cuddy cabin(if boat was a LITTLE longer).

 

If you can get a hold of some lines from a 1930s Maine skiff you can probably build a 18ft version with stich and glue. The bottom is fairly flat and probably an easy build. One of the problems I see is that with a big motor changing from motor to sail mode would not be easy. an offset motor would be a drag maybe a central motor with a high lifting mount and twin kick up rudders would work.

 

yeah, twin kick-ups seems good, and does that boat have

a dagger board. I didn't see it, but good upwind sailing was mentioned in testimonials.

MacGregor boats say they can drop the twin rudders when using the outboard for extra grip on the water.

I'd like to have ONE BOARD SIZE that could serve as:

1)one of the twin rudders(probably use just one for most sailing, lifting the one on the high side) Nothing wrong with a rudder that is a little big, some Portuguese fishing boats have just a big rudder for rudder and keel.

2)daggerboard/spudpole Maybe have twin dagger boards so the middle of the boat would be totally open. That way you could sail with just one if conditions dictate. Two shorter boards would also help sailing in shallows, which would be primary use for this boat. Twins would also help their use as spudpoles.

3)whatever they call those boards you sit on when "hiking out" for fast sailing.

4)extra bench, either across or on either side, or at front or rear of cockpit. Be able to use extra planks to create a raised cockpit floor, so you could still sail and sit in the boat, but have lot of cargo under the floor for ballast and to keep it out of the way and protected from feet.

5)extra table/counter surface(I think it would be REALLY NICE to be able to sit on a bench with nice clean flatish surface at ergo-metric 'desk height'. Multiple table top positions built in: across like a bench, on either side, or front or back of cockpit, or even diagonal.

6)kick up LeeBoards(so you could sail without worrying about crashing the dagger board on hard underwater obstructions AND be able to add "More Board" in addtion to the dagger board if conditions dictate.

7)Sculling(stern single side to side) or pulling oar with attachment of an oarshaft(sure the oarblade would be lot bigger than those racing oars, but this is a big fat boat that would need a lot of push when maneuvering.

8)Boarding/Landing planks(not just for boat to dirt, but also to throw onto soft mud to enable crossing to firm dry dirt without getting muck up to your knees).

9)Framing members of the aforementioned canopy/sun&rain shade. Maybe have small hole in the planks so they could be ganged together with either wingnut-bolts or just cordage.

10)Extending the gunnels for extra spray protection.


As you can see, I'm nuts for making something that can serve more than one purpose....especially on a small "does it all" craft. Cuts down on clutter.

Plus, a couple extra flat planks themselves sow well. Maybe just use any extras as 'flooring' so that little bit of water in the bottom of the boat doesn't get your tennis shoes wet.

Might have same size/shape boards out of differing materials for a preferred application, but they should all be able to work in any of the 10+ positions, but I'd rather go with a single highest quality version. They would be basically straight with slight 'foil', so making them of Kevlar or foam-filled titanium or epoxy coated balsa, or whatever would be as cheap and easy as that sort of thing gets. Worst case you just get a 4'x1'x1/2" piece of 7071 T7(the hard inflexible stuff) aluminum and sharpen the edges with a grinder, and drill the needed holes for mounting into the tiller, daggerboard "cap", etc. Little heavy but would work.

Maybe flat on one side and 'foil' on the other, and reversible in the rudder and dagger board sheath.



PS THIS might not be too far off the mark as a starting point, with addition of a transom for the outboard, and details like cockpit modes for the multi-position bench/table system, etc.

http://www.mboats.no/B18/Brosjyre Norsk.pdf From one of our members. I'll email him when I get a few more ideas worked out.

 

Squid,
What I referred to on page 1 re curvature was basically rocker. Yes, convex aft as viewed from the side. More curvature = lower speed. Flat or straight = 20 knots or more. Looked at the Gig Harbor "Lobster Boat" and see it's a Swampscott Semi-Dory. A very excellent boat but over $6K. As to wether a boat hull knows if a sail boat or an outboard boat I think it does. It knows because of the CG and dynamic forces in operation. On a sail boat all the forces and weight are amidships except the rudder that is very light. Hang an OB on the stern of the kind of boat we're talking about here and you need to make the hull fuller aft to carry the weight of the engine AND it's operator. The forces of the variable thrusting angle of the OB don't have enough "purchase" on the water with most semi-planing sail boats. For good directional stability the stern needs to be fuller aft. Most sail boat hulls have their fullness amidships where their weight and forces exist. So the sail boat and the semi-planing power boat require different hulls and the Swampscott Semi-Dory is the best "do it all" boat that I know of. All Semi-Dories aren't created equal however in this regard. The garboard plank needs to be warped or otherwise twisted much like in the fwd part of the boat. Also the chine needs to tuck in near the stern so max beam of the bottom is about 25 to 30% of the way fwd of the transom. With such a hull shape (in my opinion) the semi-dory should be a reasonable sailboat and also a reasonable power boat. And my earlier idea of using a Thistle sail boat was a bad one.

 

and then there is the displacement hull with fins concept.

http://www.flickr.com/photos/dansdories/3969947156/

Looks like a decent sailing hull, without the fins. Fold-able fins??? Nah, they look like they would make great steps for boarding.

Those fins look angled so they work with the boat running at a pretty extreme bow up angle.

Wonder how much they would drag if the hull was heeled over when sailing. Maybe it would reduce drag when heeled over if the tops where fattened into foils, so there wouldn't be any 'negative angle plane' on their topsides. That wouldn't effect their planning function.

 

The Gig harbor boat has a weighted CB not DB.

 

I may have found the perfect boat for this! Asking price, $50!

I figure since it was "kit built" in might be more able to take my modifications than a pro-built or mass production boat.










20' SILVERFIN SAILBOAT - $50 (los gatos)

Date: 2011-10-10, 1:45PM PDT
Reply to: sale-ewpme-2612415996@craigslist.org [Errors when replying to ads?]
20' Silverfin sailboat. Kit-built. Has trailer.
Boat needs new mast and some work. Trailer needs some work as well.
Boat has place for a motor (see photo) -- can be used as a motorized fishing boat without sail.
$50 or best offer to a good home.

Call: (831) 464-8044
(408) 436-5448

• it's NOT ok to contact this poster with services or other commercial interests