Ko Rok plays host to false killer whales 

Park chief Weerasak Srisatjang said that such an event has never occurred before as false killer whales, each the size of a school bus, never came to that area. He said it was a reflection of the abundance of resources in the Krabi sea.
Marine expert Dr. Thorn Thamrongnawasawat explained that it was very rare to see a large number of dugongs, sharks and whales in the Thai sea on the same day.
Thirty dugongs were spotted in Trang province, more than 30 blacktip reef sharks were found in Maya Bay and 10-15 false killer whales were seen in Krabi.

A false killer whale is not a whale but a large dolphin, however at six metres long it has physical similarities with a killer whale and can be found in deepwaters of open seas.