The season for whale watching in Mirissa is from November to April. Although you do come across whales from May to October as well the sea is rough during these times, which makes the journey very uncomfortable. The whale watching tour takes three to five hours and you come across Blue Whales, Sperm Whales and Spinner Dolphins also on rare occasions even the famous killer whales could be sighted. Whale watching here in Mirissa is done in an eco friendly way and is not harmful to the whales or dolphins in any way. Also, much care is taken not to interfere with the marine life.