After discovering that two reefs in the main and the smallest jib I have (110) is still too much sail on the San Juan 24 for some of the weather we get, I've decided to build a storm jib
I went through my boat files and found a photocopy from a book showing a 3-use sail: storm jib, anchor riding sail, and storm trysail.
I made a mock-up from plastic and duct tape.
The sail is only 20 square feet, which I thought might be too small for a storm jib. But a trial on the boat (tied to the dock) seems to indicate it is about right. It was pretty windy! The finished version will be cut almost flat, with hanks on the luff and a bolt rope along the foot to fit the mast slot when in use as a trysail.
Down the line I'd like to get a furler, and am trying to decide the optimum sized jib that will furl down enough and keep good shape for foul weather, yet still be sufficient (unfurled) for moving the boat in lighter winds. I don't race, so that's not an issue.
I welcome any thoughts on sizes.