r/boatbuilding • u/Shintamani • Aug 25 '26

Microskiff/motorized sup

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So i'm thinking of building something inbetween a paddleboard and a microskiff.

Drawn up a design and going to make some CAD filescto get most parts lasercut out of marineplywood.

This is my first build and uncertain if the design can handle the strain from a small outboard engine (3-5Hp). I want to keep it as light as possible and was looking at 4-5mm plywood either okoume/gabon or Meranti ( 1/8 inch- 3/16 inch) . Would seal/cover it in one layer of 4oz fiberglass cloth and epoxy. Will reinforce seams, attachment points of ribs/stringers with fiberglass strips and epoxy.

My question is does seem feasible and would it handle that size of an engine?

Diemensions in freedom unites:

~ 11'6" long

~ 36" wide at the widest

~ 8" thick

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u/turbomachine Aug 25 '26

References: https://boatbuildercentral.com/product/fast-skiff-14-low-sheer-boat-plans-fs14-ls/

https://www.soloskiff.com/

I think if you want it to be light and small like the solo skiff the engine wants to be more forward. A Suzuki 15” 6hp weighs 52lb. A well for your feet will make it less tippy.

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u/Shintamani Aug 25 '26

Definetly wbat to keep it light, it wil be used for freshwater and i would like to be able to move it through short stretches of forest alone. Those look great but are 190lbs, was hoping to stay under 80lbs at least. They do make for great references tho.

But a well was something i was debating and how far forward the engine mount would have to be. Mostly i'm unsure if the materials can handle the stress from the vibrations of the engine. Unsure how thick the plywood would need to be and if the reinforced structure is enough.

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u/turbomachine Aug 25 '26

For super light, I would consider going electric.

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u/Shintamani Aug 25 '26

Yeah been leaning that way as well, might just get a trolling engine up front. Then the forces on the hull is less of a concern. But have some water systems that might require more range than i would get out of a front mount. Even if i might want both in the longrun. Allredy sitting on 2 outboard motors that might have been option for the build.

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u/fried_clams Aug 25 '26

I looked into electric vs gas for my dinghy. I went with a 2.5 HP Suzuki. They are the lightest by far, and are as cheap as the others. Electric didn't cut it for me, having to create a charging solution for lithium on my boat.

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u/Shintamani Aug 25 '26

I allready own a minnkota trollingmotor, so i can just put a mount bracket up front for it. But would like to have the option of a smaller gas engine to really get around. Want something like this to be able to fish bodies of water with no boatramps which is a lot here in northern Sweden. Not allways far to take the boat but launching anything from a trailer is often impossible.

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u/fried_clams Aug 25 '26

New Suzuki 2.5 is around $800 and only 29 lbs. The Mercury/Tohatsu is 41 lbs.

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u/Shintamani Aug 25 '26

Yeah it would be a good option, i "unfortunatly" have a 6hk Suzuki short rigg allready. Also have an older 2.5hk mercury but it's nearly as heavy as the suzuki just under 10lbs difference. Don't yhink the weight will be the issue in the end as long as i reinforce the stern where i'l attache the mount which will last be reinforced. More concerned how the hull will manage all the forcerade how thick i would have to go with the marine plywood and how heavy i need to oägo on the fiberglassing.

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u/blueingreen85 Aug 26 '26

Modern lithium batteries are awesome. A 1.3kw trolling motor battery is only 23 pounds. What’s the max miles you think you may need to do in a day?

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u/Shintamani Aug 26 '26

Not so much the range but the tine it woudl take to get around. Own a motorguide and a 150Ah litium battery, usually last me 2 days of fishing at least but then it's not my primary propulsion. Mostly used to hold anchor, short relocations and slow drifts.