Time Out says
Whale watching or sun bathing, take your pick to enjoy the best of this beach.
Two words; Whale. Watching. But there’s always the ever so charming beach to make the most of your trip to Kalpitiya.
Be there as early as seven in the morning and head off on a boat from coast to spot the spectacular creatures of the sea, dolphins and whales. Expect to see giant flips of tails or even flashes of playful curiosities from the friendlies. February to March is the best recorded times for sperm whale sightings, and acrobatic pods of spinner dolphins. The rare humpback dolphin is also been known to show up in the waters of Kalpitiya.
November to April is recommended for calm seas and the sun kissed beach and a 160 kilometre journey from Colombo is well worth it for not only is the ocean safari breathtaking, unless your prone to a bit of sea sickness, but fun on the beach is equally pleasurable.