Harding Rock and Little Harding Rock are actually the bounderies of the shipping channel. Most of the shipping channels are 80 + feet deep. I'd add that while the rocks the italian captain hit were not marked with buoys, they were charted and there apparently was a well known tradition of cruise ships steaming closer than they should to land to provide the local village with a view of passing ships. Sounds like showboating to me. (all puns being what they are.
Sailing a '74 Challenger 40' Ketch rig out of San Francisco