This was on photobucket but was lost due to their policy change.
So I'm reposting it per request of GrafRig
Thanks. I filed this away for future reference.
The measured approach is probably the best way to get it right.
When I did mine I waited for absolute calm water and used a lead pencil to draw the actual water line on the hull.
Then I applied my blue stripe 1 inch above the pencil line (actual water line).
Many thanks!