I think they are small schools.    Marathon - about 700 (grades 6-12) Coral Shores - under 800 Key West - about 1,300

I'm always amazed there are enough kids to support three keys high schools: Key West, Coral Shores and Marathon high schools. 

If you need a backup option On October 3, Coral Shores plays against Marathon in the “battle of the Keys”!!! Monroe County longest rivalry.    https://keysweekly.com/42/sports-wrap-marathon-vs-coral-shores-historic-rivalry/

Looking at their schedule, the most competitive game at home looks to be against Jackson on October 24.    University Christian the next week would be interesting. 

It's on our "to do" list, maybe next year if not this year. We love going to KW. We made it from The Fort in 5.5 hours last time, and that was stopping for a long lunch on Islamorada. Their stadium looks nice. I think we'll make a long weekend of it, maybe finding a Thursday game in the Miami area, then leaving on Friday morning and coming back on Monday. We've seen the Conchs play a couple of times, once at PSL West Centennial and once at Southfork. Going in September or early October, the traffic shouldn't be too bad. It won't be a high level of football, but the right opponent might give you a competitive game in a unique setting.