Voyaging Outrigger Canoe from a Hobie 18 hull

Let me start out by saying that I am a poor person. Although, I am rich enough in Hobie 18 hull. In other words, I have a single one of these and was thinking about cutting off the deck and fashioning it into an Outrigger Canoe for camping excursions. I understand that the form of it is designed to go considerably faster than I can paddle. I am not trying to get the last bit of performance out of this contraption but I am looking for some feedback. It seems like it would be relatively easy to move through the water and it would hold a whole bunch of gear and water and food. And with a bit of reinforcing I could hang a tiny outboard off the back if I absolutely had to. It's 62 years of age it's nice to have backup. Has anyone seen this done before? Darts laurels and instruction are all welcome.
The main thing I guess I am looking for in posting this is an estimation of paddling efficiency relative to an expensive boat built for paddling, from someone who's knowledgeable of such design considerations as well as the shape of a Hobie 18 hull. Thank you

 

Hi CB - when you say that have a single Hobie 18 hull, do you mean this literally?
If so, do you know what happened to the other hull?
It sounds like you still have the aluminium trampoline structure to connect the hulls together?
Re converting it into an outrigger canoe, can you get hold of a suitable outrigger, or are you planning on building one?
Would you still use the existing deck to connect the new outrigger to?
Here is some info on Wiki about Hobie 18's -
Hobie 18 - Wikipedia https://en.wikipedia.org/wiki/Hobie_18
They mention that they were first built in 1976, so perhaps your hull is a bit younger than 62 years?
And the Hobie Class Association says that they were first built in 1977.....
https://hobieclass.com/hobie-classes/hobie-18/

 

Yes, I have a single hull but nothing else. I had owned a Hobie 18, actually two different ones, and sailed them years ago. My plan is to cut the deck off and glass in attachments for the cross beams/ Outriggers and make my own ama. I built a dingy using BC exterior plywood with fiberglass epoxy on both sides and it has done me well. Are you familiar with anyone having done this?

 

May be you can get inspiration from this one for you amas/akas project :
Metz Boats - Trika 540 Kayak-Trimaran http://www.metzboats.de/htm/designs/multihulls/trika540/trika540.htm

 

Thank you, I will check it out. What do you think the paddling efficiency of such a hull would be? That's really kind of what I'm searching for here. I understand it won't be as good as the latest computer generated vessel form but I don't want to bother with it if it's going to Pedal like dragging a couple cinder blocks through the water. Any thoughts? Thanks

 

I'm not very Hobie literate and I see pictures of two different types, one with a daggerboard and one without. Beware the one without; it is asymmetric in shape and how it will handle as a single hull with outrigger would be hard to determine before hand and will depend on which hull you use.

OTOH the daggerboard style hull should be quite suitable for a single hull with ama. Some consideration should be made for reinforcing the edges of any deck opening.

 

I apologize for not posting a photo of a Hobie 18. This computer stuff befuddles me. You are correct that it is the daggerboard hull. I had thought about a homie 16 but quickly struck that because of the asymmetric home which would create a good bit of form drag I would think. I will be reinforcing the rail with one by two wood of some type or another. Thank you for your input and any other suggestions that come to mind I would welcome.

 

Do you want it to sail too or just paddle?

 

I've pulled them apart before. The inside is just a veil over foam. You will have to laminate the inside properly. And you will need to make gunnels and frame for the outrigger akas. I'd probably leave about 2 feet of the deck on both ends and plug them off and fill with foam. You could make two cutouts and leave a thwart as well. That will save you a bit of money, but not time.

 

I had thought about leaving a little bit of a four deck to kind of help stiffen the nose. I'll probably rig the transom for a little four-horse motor since that is what I own. The 15 would probably be a bit too much haha. Given the waterways I'd be likely to use it on, foam would be unnecessary. I had also thought about popping a mold off of it so that I could make a much lighter boat as I figured the hole is going to weigh 150 lb. The stresses of all of that sale area and pounding through Seas at 15 plus knots requires a lot thicker build up than me and my paddle would.

 

Paddling although I would eventually probably have some kind of sail assist for running dead downwind or a broad reach. But primarily paddling

 

The outboard would do better if fastened on the stern ama alongside the main hull.
Adding the outboards weight to the transom will throw the trim off, and it may get dunked.
Even in sailing mode, all the old Hobie cats sit very low in the stern.

 

Yes, and make sure the tiller handle is on the right side of the engine. IOW, put the ama on the side that puts the outboard's tiller towards you. Not too many fours out there, you got an old Johnson/Evinrude two cylinder from the 70s or 80s ?

 

Buy Gary Dierking's book on outrigger canoes, there you can "steal" ideas how to build iakos, lightweight foam & glass amas, sailing rigs and side mounts for outboard motor which works well, as previously said 4hp on the stern of hobie 18 is a bad idea.

 

As my first hurdle was to make sure that the thing would paddle decently, I hadn't really given it much thought yet but, given the motor I will be using is a 1976 beautiful little four horsepower Johnson that rotates 360° for reverse, I would probably build in a place to fasten it on Alma side of the main hall right by wherever I am likely to sit which will roughly be midship