Ed wrote:

Is this event held over line-of-sight water? If so, the FRS radios
should work, though close to maximum range there. If there is
terrain or just trees in the way, then 2 - 3 miles won't work. Be
easy enough to probably get a pair to check the path over your
maximum range, though.

There is a slight outcropping between the start and finish which is probably
enough to rule out the FRS radios.

As others have said, you'll get a much higher quality
communications system if the local hams do it.

I have contacted them and will see what they say.

Mitch