I need an excuse for not going swimming tomorrow! ( i cant swim)?

Question

im 13, and in grade 8

tomorrow my class is going swimming, the shallowest water is 8 feet and im onlt 5'3 or so. I panic in deep water and i cant swim, my friends always get mad at me and say "everyone can swim" but i honestly dont know how, the most i can do is float on my back but i need an excuse to get out of it

A REALLY BELIEVEABLE EXCUSE !

thanks! :|

Answer 1

 I dont wanna go swimming either but its jst i dnt knw an excuse