From August to October, humpback whales arrive from Antarctic waters to calve in the warm Pacific shallows off Gorgona. Mothers bring their newborns close to the island, and during peak season you can hear the whales singing while swimming in the bay. On clear mornings, breaches are visible from the beach without binoculars.
Boat trips depart when conditions allow — park guides lead them and know the waters well enough to position the boat at a respectful distance without disrupting the whales. The trips last two to three hours and typically encounter multiple individuals or pairs. Sightings are not guaranteed, but the failure rate is low during the peak weeks of September and early October.
Outside whale season, the boat circuit around the island still has a strong chance of dolphin sightings and is worth doing for the sea views and coastline alone. The whales are the headline reason to time your visit for August to October, but Gorgona has enough going on that any month is justified.