I looked around OC doing IG search in FCC database and lots of listings for
Condos and some businesses in the 450MHZ range.. Nothing on Castle in the Sand but
their is a private company that leases radios down that way you might want to try..
Course some may be DMR digital now so you need a good scanner capable of that.
I would do search in the 450-470 MHZ range down there as well.
In some places, I usually just ask one of the guys to show me his radio, then look it up and see what frequencies it covers, then search that range. Sometimes I can get one to key up while I stand there with close call. All they can do is say no.
Frequency for Castle in the Sand found using Close Call: 464.55. I spoke with one of their personnel and it's the only channel they use. I want to thank everyone on this thread for their help and recommendations.