Half Moon Bay

Almost all of the beaches are on or off of Highway 1 a.k.a the Pacific Coast Highway Note some addresses are given as CA Highway 1, the Cabrillo Highway or the PCH.

Bean Hollow State Beach & Pebble Beach
Off of Highway 1. Phone: 650-879-2170 (http://www.parks.ca.gov/d...) Due to the heavy surf and rip tide, swimming is not recommended. You can explore the self-guided nature trail.
Cowell Ranch State Beach
Off of Highway 1, Phone: 650-726-8819 The entrance to Cowell Ranch is a fairly long hike in and leads to cliffs overlooking the ocean. It is a steep hike down to the beach.
Dunes State Beach
Highway 1 to Young Avenue. Phone: 650-726-8819 (http://www.parks.ca.gov/?...) Sister beach of Venice State Beach and Francis State Beach. Part of the Waterfront Coastside Trail system.
Gray Whale Cove State Beach a.k.a Devil's Slide
Highway 1, Phone: 650-726-8819, (http://www.parks.ca.gov/d...). The two nick names derive from the fact that 1) gray whales can be seen from the beach and 2) there are steep landslide trails. Note – this is a clothing optional beach.
Fitzgerald Marine Reserve at Moss Beach
Highway 1 in Moss Beach. Phone: 650-728-3584 Docent tours are availed to take you through the nature trial and marine preserve. Lots of geologic formations are here and at the point you can see the San Andreas Fault peeking out. Great tidepools, walk out and see the sea urchins, starfish, and anenomies when the tide is 0 feet or lower.
Francis State Beach
From Highway 1 to Kelly Avenue, Phone: 650-726-8819 (http://www.parks.ca.gov/?...) Sister beach of Venice State Beach and Dunes State Beach. Part of the Waterfront Coastside Trail system. Also home of the Half Moon Bay State Beach headquarters
Montara State Beach
Highway 1 at 2nd Street, Phone: 650-726-8819 (http://www.parks.ca.gov/d...) One of the more popular beaches in Half Moon bay due to easy access and low hills, the beach provides opportunity for swimming, exploration of tide pools and surf fishing. There is also a lighthouse at Point Montara that has been converted to a bed and breakfast.
Mavericks & Pillar Point Marsh
Highway 1 to Capistrano Road to Pillar Point Harbor. Phone: 650-728-3584 Home of the legendary Mavericks Surf Contest (http://mavericks.bolt.com) This area NOT recommended for swimming. Technically it is not recommend for surfing either but the people who compete in the contest are professional and a tad crazy. The huge crashing waves are a site to see.
Naples / Roosevelt State Beach
Highway 1 to Washington Boulevard to Naples Avenue Phone: 650-726-8819 Part of the Waterfront Coastside Trail system.
Pescadero State Beach
Highway 1 to Pescadero Road Phone: 800-444-7275 (http://www.parks.ca.gov/d...) Explore the tide pools or watch the waves crash along the rocks. It's a great place for bird watchers. Sister beach of Pomponio State Beach.
Pigeon Point Beach
Off of Highway 1. Home of the Pigeon Point Lighthouse.
Pomponio State Beach
Highway 1 to Pescadero Road, Phone: 800-444-7275 (http://www.parks.ca.gov/d...) This beach is at the base of sand stone cliffs that are not as hard to reach as steeper trails. Sister beach of Pescardero State Beach.
San Gregorio State Beach
Highway 1 to Highway 84 (http://www.parks.ca.gov/d...) Discovered by Explorer Gaspar de Portolá in 1769, the beach is strewn with driftwood and there is also a bird sanctuary. Note – this is a clothing optional beach.
Venice State Beach
Highway 1 to Venice Boulevard, Phone: 650-726-8819 (http://www.parks.ca.gov/?...) Sister beach of Dunes State Beach and Francis State Beach. Part of the Waterfront Coastside Trail system.
Waterfront Coastside Trail
Pillar Point Harbor to Mirada Road. Phone: 650-726-8297 The trail systems goes through Naples / Roosevelt Beach, Dunes Beach, Venice Beach, Francis Beach and Bluff Top Coastal Park.