The good news is that you appear to have a bias-cut sail with the tear running along the warp of the fabric. That means it will be easier to patch without degrading the shape of the sail.

A fellow Isotope skipper tore his mainsail shortly before the National Championship this year. He has a radial-cut sail and his tear crossed multiple panels. The patch, although strong enough, altered the camber shape - badly.

I had sewn myself a new mainsail this year so I loaned him my older main (which is still in good shape and I keep as a spare) with the caveat that if he won with it, I'd auction the mainsail off on eBay afterwards. Fortunately (with the help of my lucky hat), I manged to eek it out ahead of him so I get to keep the sail.

Good luck,
Eric