Offhand, I don't know of any campgrounds in the Shore/Atlantic region that would allow you 1 large dog, let alone 3.
However, in the Southern Shore area, I camped at Seashore Campsites in Cape May with my Black Lab. It's been a few years since I've been there and I really never took notice if they have a limit on the number of dogs you can bring.
Cape May State Park allows dogs on the beaches during OFF SEASON only.
Higbee Beach Wildlife Management Area in Cape May allows leashed dogs regardless of the season.
I don't know if you've ever been to this website, but they have a ton of Pet Friendly Information that may be of assistance to you! http://www.dogfriendly.com/server/travel/g...chstateNJ.shtml