Mizen staysail for Shannon 38

I own a Shannon 38’. She is rigged as a Staysail Ketch. This boat is rigged to have a mizzen staysail. However, the sail did not come with the boat. The halyard is there with the blocks for the sheets.

Looking at the original design, it did not come with a mizzen staysail. i.e. as far as I can tell. Just wondering if I should bother with the mizzen staysail or not. I’m already rigged for it. So what size should this sail be.? How are these sails measured.? Any info could help.

Your best bet is to talk to a sailmaker. He will have to come and look at the boat and measure things. Mizzen staysails can vary a good bit, depending upon the owner’s desires and the boat’s design, so the cut and size are not set in stone, even if the Naval Architect drew a sailplan that included one. Where the sail is tacked to the deck can also change how it works. Mizzen staysails, done right, can add a half knot to boat speed. Getting them cut and set so as to do that is not necessarily easy.