Thank you!Sailrite has kits that are based on the length of your boom also. They also put them together for you for a fee of course. This might be a bit long but, it is the smallest they make. http://www.sailrite.com/Finished-Sail-Cover-for-Booms-to-10-Feet
Thank you Ward!Do a google search for Lee Sail Covers. They have instructions for measuring your mast and boom w/ sail on. Also have pretty good pricing and quick delivery.
Got one from Lee for my first boat.
This time I went to Linthicum Sailmakers in Somerdale NJ. Brad Linthicum is very good to work with and very high quality work and materials.