Every July, tens of thousands of visitors descend on Colombia’s Pacific Coast, crowding the frenzied passenger docks in the seaport of Buenaventura as they wait for speedboats that will whisk them to the small communities lining remote Málaga Bay. They’ve come to see the humpback whales.

The whales, numbering in the thousands, are on their own mass mission: migrating from their feeding grounds near Chile to their breeding grounds near Colombia, where they remain until October.

During the whale-watching season, which begins in mid-July, boats with licensed captains and guides take the visitors — mostly Colombians but a growing number of foreigners — to see the creatures breach, blow and slap the water with their fins and tails.

On shore, visitors can also witness a lesser-known spectacle as residents of the area gather for an annual festival to celebrate the whales and revive a fading culture.