International Sign language class

In my high school, we were required to take a foreign language. We got to choose between French and Spanish. I chose French. Once I clumsily helped a drunk Frenchman find his destination on the subway map, but otherwise have never used this knowledge.

I believe it would be much better if the mandatory foreign language taught to high schoolers were International Sign language. Similar to French or Spanish, this would help you communicate with people of other cultures. Unlike French or Spanish, because it would also be taught to all other high schoolers around the world, it would be a universal language to communicate with anyone, not just French or Spanish people.

Also, since it's a fundamentally different mode of communication than speech, it would also be useful for communicating in a variety of situations in which all spoken languages fail: In loud bars/clubs/construction sites, when trying to be very quiet, while underwater, while eating/choking, through optically transparent but acoustically opaque barriers, etc., etc. The applications are endless.