Sea Paradise Sailing and Snorkeling has a morning snorkel tour that goes to the famous and beautiful Kealakekua Bay.
Here’s good article from Hawaii Top Ten on the Kealakekua Bay Marine Preserve.
Kealakekua Bay is steeped in Big Island and overall Hawaiian history. The Bay and surrounding Historic Park is the site of the first extensive contact between Hawaiians and Westerners with the arrival of Captain Cook in 1779. Activities here include kayaking, dolphin watching, historical sightseeing, scuba diving, and snorkeling. Several boat tours are available, as are several kayak rental services for the more adventurous. The kayakers enter the water at an old pier and make the fun and adventurous paddle across the bay to Captian Cook’s Monument and the Marine Preserve. Or several power and sailboats of differing sizes and amenities arrive here and make a few hours of snorkeling and time on the water convenient.
The historic Hikiau Heiau, site of the first Christian funeral service, is located here. This funeral service led to the first realizations by the Hawaiians that Captian Cook and the white visitors were not the Gods they had been expecting. He and his crews on the Resolution and Discovery sighted Kealakekua Bay on the morning of January 17, 1779. He estimated several thousand people lived in the two villages.
Cook had entered the bay during Makahiki. This was also a traditionally peaceful time of year, so he was welcomed and given food. Cook and his crew stayed for several weeks, returning to sea shortly after the end of the festival. After suffering damage during a storm, the ships returned two weeks later, on February 14. This time relations were not as smooth. The Hawaiians suspected that a God would not suffer and be constrained by such mortal damage.
After the theft of one of Resolution’s small boats by a local native Hawaiian, Cook attempted to lure Hawaiian chief Kalaniʻōpuʻu aboard to hold as hostage until the boat was returned. A skirmish ensued during which Cook was struck in the head and stabbed, near the spot where he had first set foot on the island.