The quarter-mile stretch of beach is named for the countless small to medium-sized rocks, rubbed smooth from years of rolling through ocean swells, that cover it. This is one of the most popular bail-out dives on Cape Ann, mostly due to the free parking located along the beach and shelter from northern exposure.
a 150-yard swim straight out over a gently sloping, sand/gravel bottom takes you to a band of medium to large rocks running parallel to the beach interspersed with grasses. There’s a second band another 30-40 yards out with similarly sized rocks. There’s little in the way of invertebrate life and visibility is often poor due to the surge and swells. The best diving is found well to the right (west) of the beach, near a ledge that breaks the surface of the water a couple of hundred yards offshore. Depths throughout the area reach 30 to 35 feet. The sight is relatively bland compared to Loblolly to the North and Bass Rocks to the South but its a decent dive when the water is calm and visibility opens up and a go-to spot when sites with northern exposure are blown out. Divers frequently encounter pipefish, moon snails, and skates roaming between the shore and the rocks.
The walk from the road to the water is down the short sloping pebble beach and is moderately strenuous. Entry and exit are made over smooth rocks or sand depending on the tide and recent storm action. At high tide, the water gets deep quickly leaving little room to sort out your gear. Do as much as you can before getting in. The site is prone to swells, so entry and exit — particularly exit — can be difficult. If surge picks up and you fear that you cannot get safely ashore, look up and down the beach for any stretch of sand. There's often sand at the left (eastern) end of the beach. Make your way through the shallows to it. It may be the only soft landing you'll find.
The beach is south facing and highly exposed to wind from any southerly or easterly direction.
If there is any weather off-shore, the site can be quite surgy and surf can build-up quickly. The beach entry is usually quite simple but in waves, it can challenge even experienced divers. Though it is not recommended since there are plenty of alternative sites with no southern exposure, if you chose to dive here when there is surf, make sure to keep your fins on your wrists and mask and snorkel/regulator in as you work your way through the surf. Be prepared to be knocked down. Once in the water, the dive is reasonably shallow. Visibility can be reduced quickly with the silty bottom so be prepared to work at staying in your dive team.
There is free parking along the western end of Penzance road along the beach. There is a sign that marks the resident only section.
Note, Penzance road is marked with a do-not enter sign at the eastern end (closest to Loblolly) so it is effectively one-way. If you're navigating, the software may not be aware of this restriction so make sure to approach from the west. Penzance road has a tendency to be washed out in winter storms. If you arrive on a northerly windy day and can't access the beach you'll want to move to an alternative site like Stage Fort Park.
Jerry Shine provided much of the written dive site content on the shore diving sites around New England from his 2005 publication: A Shore Diving Guide to New England which is currently out-of-print. His 2017 publication A Year Underwater: Twelve Months of Diving, Fraternizing with Marine Life, and Just Having a Great Time, from the St. Lawrence River to West Palm Beach is available for purchase on Amazon.
If lobstering be sure that you are licensed, have a gauge for the area you are lobstering in, have your numbers on your cylinder and flag, and don’t land any shorts, longs, notches, or eggers. For more information please reference the mass.gov regulations site here.