CSA has no a/n beach. While some nearby resorts may have a/n beaches, they are reserved for guests of those particular resorts, just as CN's a/n beach is reserved for guests of Couples.
If you were at CN, then you were on Seven Mile Beach. Seven Mile Beach is comprised of Long Bay, which is about five miles in length and is the bay upon which CSA sites, and Bloody Bay, which is approximately two miles in length and is the bay upon which CN sits.
I know everything, and I'm always right (just ask my husband).