Although a wall dive is always fun. Black Rock suffers greatly from over exposure to people. For rounding the point, north to south, this is a beginner dive or intermediate snorkel. The north side (best entrance) has a lackluster entry (sand bordered by a man-made jetty) shifting to a reasonable natural wall as you round the first point. The best views are right on the wall. Look for small fish, eels and corals in the nooks and cranny's. Small turtles frequently visit the wall near the surface to feed (we saw two). Watch for a large alcove on the main face of the wall. Not much to see but fun to stick your head in. The problems occur as you approach the south side and the exit. The visibility drops from 50-60 feet to 10-20 feet and the number of people climbs to unbearable levels. More turtles can be found in the shallows against the rock but in this area, they will be mobbed by tourist snorkels with no respect for any animal (You included. Lots of pushing and shoving to get that photo with the turtle). I found better snorkeling and diving, a half mile to the north at old airport beach. Free parking, easy access, shower, shallow beginner dive (eels and octopus plus a wide variety of fish).