google images of a Nautical Star. It is a standard 5 point star but each point is split into two colors.
http://www.google.com/images?hl=en&q...w&ved=0CBsQsAQ
You can find paper pieced patterns on line. Here is a 10" one
http://hotpinkpeonies.blogspot.com/2...lock-five.html
Edited to add, that Judy Mathison's book Mariners Compass Setting a new course gives very good instructions on how to draft one as well as draft any Mariner's compass. If you are interested in making Mariner's compass quilts that book is a must have.