Full hookup / dry, length, "on the beach" or near a beach, minimum facility requirements?
On the beach -- forget it. Look at the San Diego County Parks
website for some suggestions.
1) Guajome County Park
in Oceanside usually has space
2) Mission Bay RV Resort Camping
- maybe but close in and crowded
Best bet is to go east (San Diego county stretches from the Pacific Ocean to the Anza Borrego Desert). Lots of places near Ramona and Julian.