Bernie Cook wrote:

I have a friend of mine that does a lot of boat repair and canvas
work on them as well .He is getting into boat building as well and he is
looking for a type of adjustable curve or batten for laying out long
curves and being able to put on the wood to transfer it


I think the traditional tool for that purpose was a wooden batten. Just a
piece of straight, straight-grained wood that seems to bend in a nice way.
I guess some old books on lofting would tell you all that you ever need to
know about those.

Enjoy!

Heikki