Most diving is done in the cove on the north side of the point with a maximum depth of about 70 feet.
Nubble Light is a good dive site for instructors because it's an easy entry shore dive in a protected cove and plenty of sea life to observe.
There is plenty of ocean life from lobsters, to wolf fish, torpedo rays, sea anemones as well as fan worms.
Parking does become an issue if you get there much after 9AM. There are two parking areas, the top lot has a 2 hour limit and the lower lot, near the entry area doesn't have a time restriction.