Possibility of homebuilt plywood modern dinghy

[Muaddib1116]

I suppose I see the modern rigid dinghy designs as rough analogs to the capabilities of a RIB, but without the vulnerability of tubes. High load capacity, high interior volume (usually higher than RIBs because of the space under the gunwales), 10-12ft long, room for 4-6 adults, can plane when pretty loaded up, with a 10-20hp motor and run at 15+kts, able to operate well in some decent chop not just calm conditions. I like the OC tender design for the wide gunwales that approximate the tubes of a RIB and offer outboard seating. The tallish flat sides increase outboard buoyancy compared to traditional rowing/sailing dinghies, allowing a person to step on the gunwale and not flip the boat. They also allow for a wide surface to afix a large bumper to protect mother ships.

A few of you have stated that there's plenty of designs out there. Can you post some examples of what diy dinghy designs you think make good cruising dinghies, analogous to a 10-12ft RIB?

[psk125]

There are hundreds of designs that you could choose from. WoodenBoat is just the tip of the iceberg.https://www.woodenboat.com/boat-plans-kits. Chesapeake Light Craft (https://clcboats.com) could keep you busy for weeks, just looking. Leo Sampson, from Tally Ho, likes the PT 11 that they offer - but it's not cheap. For more complicated shapes you can use strip-planking/epoxy techniques too. At the other end of the spectrum are the quick & dirty. I led a troupe of 5th graders building this:https://hvartial.kapsi.fi/dinghy1/simboii.htm it took us four morning sessions (Mon-Thu) of a summer camp to build it, caulk it and paint it inside & out. On Friday morning we carried it down to a pond and rowed around in it. You pays your money and you makes your choices.

[Muaddib1116]

Originally Posted by psk125

There are hundreds of designs that you could choose from. WoodenBoat is just the tip of the iceberg.https://www.woodenboat.com/boat-plans-kits. Chesapeake Light Craft (https://clcboats.com) could keep you busy for weeks, just looking. Leo Sampson, from Tally Ho, likes the PT 11 that they offer - but it's not cheap. For more complicated shapes you can use strip-planking/epoxy techniques too. At the other end of the spectrum are the quick & dirty. I led a troupe of 5th graders building this:https://hvartial.kapsi.fi/dinghy1/simboii.htm it took us four morning sessions (Mon-Thu) of a summer camp to build it, caulk it and paint it inside & out. On Friday morning we carried it down to a pond and rowed around in it. You pays your money and you makes your choices.

Can you pick a design to share with us that you think gives similar utility to a 10-12ft RIB?

[rslifkin]

If I were going to do it, the design would probably be close to the ASTender, maybe with a little bit of the flat planing pad of the OC Tender if I thought it wouldn't make the ride too hard at higher speed.

I'd probably just spitball the design, but I'd be aiming for a plumb bow with a fairly fine entry twisting out to a moderately low deadrise further aft. Spray rails or a slight reverse chine forward, then a small-ish chine flat carried all the way aft. Transom for the outboard set forward between flotation pods. About 12 feet LOA to the end of the pods, somewhere about 5 - 5.5 ft beam. Probably a slight taper in aft and maybe a hair of rocker to help low speed efficiency but still allow planing. Goal would be to get good load carrying capacity, a decent ride on plane, but be easily driven so it doesn't need a huge outboard.

[ggray]

Yes, check out CLC. Many choices. I wondered if someone was going to mention the PT 11. Very well designed this boat is.

I was thinking the PT11 would meet your specs until I read "room for 4-6 adults". I doubt that is possible in a wooden "dinghy". My 11.5 foot RIB is capable of handling that kind of weight because of those air tubes and the stability they offer. Your desired speed would require a RIB. A "hulled" boat would probably need to be at least 15 feet long I'd think.

[Muaddib1116]

Originally Posted by ggray

Yes, check out CLC. Many choices.

Can you suggest a few of their designs that approximate a 10-12ft RIB?

[Muaddib1116]

Can you even mount an outboard on a PT11? Honestly, this boat is so far away from what I've been talking about, I dont understand how multiple people are recommending it.

[Woody]

Originally Posted by Muaddib1116

I suppose I see the modern rigid dinghy designs as rough analogs to the capabilities of a RIB, but without the vulnerability of tubes. High load capacity, high interior volume (usually higher than RIBs because of the space under the gunwales), 10-12ft long, room for 4-6 adults, can plane when pretty loaded up, with a 10-20hp motor and run at 15+kts, able to operate well in some decent chop not just calm conditions. I like the OC tender design for the wide gunwales that approximate the tubes of a RIB and offer outboard seating. The tallish flat sides increase outboard buoyancy compared to traditional rowing/sailing dinghies, allowing a person to step on the gunwale and not flip the boat. They also allow for a wide surface to afix a large bumper to protect mother ships.

A few of you have stated that there's plenty of designs out there. Can you post some examples of what diy dinghy designs you think make good cruising dinghies, analogous to a 10-12ft RIB?

Your list of requirements in a good place to start with a boat designer. You might consider starting a thread over to boatdesign.net. They are an extremely knowledgeable community that can be very helpful. They will also be able to point out the weaknesses or trade offs of these designs, if there are any.


To me, going from full carbon to plywood, the weight is going to be the issue. More weight means more HP, means more weight.....

[ggray]

I mentioned many choices so you could see what happens with changing the parameters. Their 15'2" Peeler Skiff might meet your criteria, but it's over 300 pounds, I assume w/o the motor.

I think Russell powered a PT11 with a small propane ob to see what it would do, but that isn't really what the boat is about.

Russell's design is really sophisticated as any good boat needs to be, but with ease of construction kept in mind. Look at the differences between the nestling PT11 and the non-nestling version, the Spear. Totally different interiors and he tells you why. His instruction manuals simplify as much as possible, and you learn a lot. I built his 18.5 ft PT Skiff kit (no longer available) so have seen this first hand.

[grantmc]

Am I missing something with his thread?
There are several easily accessible free plans available to build plywood dinghies.
Here's an example of the original plans for an Optimist Sailing Dink.

[Muaddib1116]

Originally Posted by ggray

I mentioned many choices so you could see what happens with changing the parameters.

Where was this?

Originally Posted by ggray

Their 15'2" Peeler Skiff might meet your criteria, but it's over 300 pounds, I assume w/o the motor.

I think I'm gonna need a bigger boat.

[Muaddib1116]

Originally Posted by grantmc

Am I missing something with his thread?

Yeah, you definitely are. This thread and all my posts in it are about the possibility of building a diy dinghy that approximates a cruising dinghy, ie. a 10-12ft RIB or one of the new rigid dinghies I mentioned earlier, specifically not traditional rowing/sailing dinghies. And somehow that's turned into a bunch of people posting links to sites specializing in home built rowing/sailing dinghies, saying there are plenty of plans out there that cover what I want. I ask for specific examples, and you guys bring up the PT11 and an opti sailing dinghy.


The ripple tender linked by Leadfree is the only suggestion so far that makes any sense, given the purpose of this thread.

[Tupaia]

The best one I have seen is from Tendercat, finished, kits and plans. Very very light and stable low tech simple plywood construction.


https://domimontesinos.com/tendercat...nte-et-legere/

[bergius]

We built a nesting dinghy last winter, though maybe more traditional than modern (same model as in that Sailing Florence video shared above). Fits nicely on our foredeck, and both sails and rows well. Would probably also behave well with a small outboard, but so far sailing has been our way of handling the longer dinghy rides.




We built ours from full sheets of marine ply in exactly a month. Buying a pre-cut kit would've likely made it slightly faster.

The dinghy carries three adults comfortably when rowing, and two while sailing.

Details and a build log can be found from https://lille-oe.de/dinghy/

[Muaddib1116]

Originally Posted by Tupaia

The best one I have seen is from Tendercat, finished, kits and plans. Very very light and stable low tech simple plywood construction.


https://domimontesinos.com/tendercat...nte-et-legere/

Thanks. The site is pretty light on info on it, but the 3.3 model might be practical. The hulls seem very narrow, and the central tunnel quite large. The Ripple tender from Spirited yachts seems a little more polished of a design, and they also offer kits.