Boat Plans

I was looking at the US1M plans on the AMYA site and a question popped up. Are the shadows that are shown the final hull size or have they already been reduced to allow for the thickness of the planking? The reason I ask is that it is not mentioned on each plan what size planking is to be used. In the generic construction files it says 1/8" but unless this is a standard for all plans it leaves you up in the air. I did a rough calculation(in my head so it’s questionable) and an eighth for the the wetted portion of the hull worked out to about 20 cubic inches. I converted that to weight and it is 11 ounces. This is subtantial. Anyone straighten me out?

Hi Don,

The convention is that the lines are the exterior hull lines (and not reduced for the planking unless specified, in which case the plan thickness should be included)

If you don’t have an IOM yet, then why not consider an IOM rather than a US1M and come sail/race with the quickly growing group of IOMs on the island. We have had 14 local boats at an event . . more are always welcome.

I thought that was the case but the patterns in the plans(Mistral for example) show notches for stringers which led me to beleive that they were actual templates. Now I’m more confused. I sure wish I could get on the
US1M forum.
Where do you sail in the summer? I’m in Campbell River and there are only 3 boats here that I know of and they are US1M sort of.

Hi Don,

I am in Parksville. There are a couple of IOMs in Courtney, one on Hornby Isl. The rest are in Nanaimo, Victoria and on Salt Spring Isl.

We have started a spring series that moves to different locations for 5 regattas. We also get together a few weekends in the summer and fall.

We held the Canadian IOM Nationals on Salt Spring this year and with 18 boats (for as far as Ontario and California). We hope to have it again soon.

Lori Neish on Salt Spring has several moulds and can produce an inexpensive hull for you as part of a project to introduce IOMs to the area.

Let me know if you want more info and I will put you in touch with Lori.


Here is a contact in Courtney

Ray Kretchmar

kretchmar at (put in the @ sign)

Ray will be pleased to speak with you and show you his boat. It is out of one of Lawrie’s moulds.

I sent you a PM