A couple weeks ago we purchased a used, 1973, El Mar Boat company - Sundance Model 20 , Mono Hull Sailboat.
I’m going to use this area as a repository for any information I can find about these boats.
Some general background:
El Mar Boat Company was founded in Roseville, MI. They produced three models.
Sundance 16 (First produced in 1973)
Sundance 20 (First produced in 1972)
Sundance 23 (First Produced in 1975)
(Much of the data here was found on Sailboatdata.com)
In addition to this, the Sundance 20 also had a “weekender” version which had an extended cabin.