A favourite place, Kelakekua Bay on the Big Island. It was the site of great tragedy when Captain Cook's blood was spilled in 1779. Today it has some of the best snorkelling reefs on the island. The nearest shore access is a mile from Cook's monument. From there you can swim or take a boat to the reef. Spinner dolphins are often seen in the bay too.
See that steep cliff on the far side of the bay? As we saw last year, lava flows like this one (below) form benches at the shore that can collapse and break off. The Big Island is less than one million years old, a baby in geological terms. Kealakekua Bay was created just 120,000 years ago when a 30-km chunk of the shore broke off and slid into the sea. The resulting tsunami completely submerged the island of Kaho'olawe, 1427 feet high! The wave continued and nearly inundated the island of Lanai. Today on Lanai you can still find chunks of coral at the 1000-foot level.
Diving around the island opens our eyes to a new world. The undersea shoreline around the Big Island is dotted by slide zones. Many times submerged landslides have caused tsunamis to march across the Pacific. In 1964 a tsunami begun in an Alaska quake killed 11 people in Crescent City, California. Soon we will see that even New York City lies in the path of a tsunami.