I actually think Diver's Cove is probably the most benign dive in Laguna (any maybe SoCal). We were there the weekend before last so my wife could try doubles for the first time. It's shallow, an easy entry, and mostly sandy bottom.
If you do, however, get too close to the wall where Giggle Crack is, I can see it becoming dangerous. I would certainly avoid that part of the site.
Edit: Here are better links to the site in question:
Diver's Cove
Divers Cove: Laguna Beach, California
Rainer, could you help us understand where this Giggle Crack is located?
giggle crack, laguna beach, ca - Google Maps