JEM Watercraft

Hi guys! I ran our 8HP OB this afternoon since I'd not run it for awhile. We still don't have a boat for it. I went around my usual set of favorite sites window shopping for an appropriate boat.

My strange question is: Can I scale the DK 15 so it will handle the 8HP OB? What scale factor would you recommend Morten?

Hi Louis,

Yes, you can scale the 15' Dinghy. In fact I have all ready done it for you

Please have a look at the 18' Dinghy:

http://www.boatplans.dk/boat_plans.asp?id=56

How did I miss that?

Just the same Morten, what scale factor would you say would be a good number to use so an 8HP would not over power the DK15 hull shape?

I ask because the power range of the DK18 is 6-20 hp, which puts my motor in the lower range.

I think you missed this one, Morten. Even though I've upgraded, I'd really still like to know. Of course if it is too much work to calculate it, I'd settle for your educated guess. My amateur guess is I could scale by 10% so the beam would be 1125 mm and the overall length would be 5020 mm.

I did not ask about shrinking the DK18 so it better matches my motor because the beam would shrink which would make it less stable. Scaling up the DK15 would increase stability I naively assume.

Yes, I missed that one, sorry.

You could scale the 15' by 10% and getting a more suitable size for the outboard you have. However if doing so I would suggest you add some kind of motor well structure or other reinforcement because of the increased force from the outboard.