See Blue, and Sperm Whales off the southern coast of Sri Lanka
Sri Lanka has the largest, and it is believed, only resident population of blue whales in the world, which are best seen off the southern coast between November and April, when the sea is calm. December and April are peak months due to whale migration, when blue and sperm whales may be seen together. Bryde's, fin, sei, sperm, and killer whales, along with spinner dolphins, flying fish, and manta rays may also be seen year. Whale/ dolphin watching excursions take place off the Southern, and Eastern coasts (October - March), with some operators going out all year. The ideal locations for whale watching on the southern and eastern coasts are Dondra Point (accessible from Galle, Hikkaduwa and Mirissa) while the sea off Kalpitiya to the east teems with an abundance of dolphins, and research is suggesting is the best place to see pods of sperm whales. On the west coast, Trincomalee is the best location to go out whale and dolphin watching from (May-August).