Oahu has more than 100 miles of coastline and 100 beaches. Visitors to many of these beaches generally find excellent possibilities for swimming, diving, snorkeling, bodyboarding, surfing, and fishing. People looking for the best beaches for snorkeling or diving should look for easy public beach access and also water depths of 15 feet or more, ideally reefs within swimming distance, and interesting underwater topography.
Many of these conditions can be found at beaches somewhere within the four major areas of Oahu – North Shore, Leeward Coast, South Shore and Windward Coast. Shoreline access for snorkeling or diving can be a problem along some coastlines for various reasons – long swims, too rocky or turbulent, too shallow, too busy with boating, wrong current direction or speed, waves and surges, tide and surf conditions, and other factors.
The South Shore of Oahu has only a limited number of dive and snorkeling sites accessible from the shore, including from Waikiki Beach. But Hanauma Bay Nature Reserve makes up for other shortcomings, although it can get very crowded. Waters of the Bay are full of tame fish. The only caution for snorkelers or divers at the Bay, like anywhere else, is to not get carried away and exceed their capabilities.
The Windward Coast is different from Oahu’s other coasts. It contains several fantastic stretches of fine white sand and other beaches and waters usually are calm in the early part of the day. Snorkelers will particularly love Kailua Beach and Lanikai Beach.
On the Leeward Coast, near Ko Olina Resort, diving usually is excellent year-round, and also snorkeling, especially at Kahe Point Beach Park, nearby Electric Beach, and Makaha Caverns. The Leeward Coast has a number of other very good diving locations that can’t be recommended for snorkeling, like Keaau Beach, Makua Beach and Yokohama Bay where the Waianae Mountain Range meets the ocean.
Especially from May through September, beginner snorkelers and divers up to intermediate levels will have excellent choices on Oahu’s North Shore. These would include Mokuleia Beach west of Waialua; the north and south reefs of Waimea Bay and also Three Tables (part of the Pupukea Marine Life Conservation District) and Shark’s Cove.