Bay of Biscay Seabird Pelagic

Aves Cantábricas runs guided marine seabird observation boat trips from Santoña, Cantabria, into the Bay of Biscay (Mar Cantábrico), reaching approximately 12 nautical miles offshore into the open Atlantic shelf waters. Led by Director and specialist guide Alejandro García, the trips run aboard the Calidris — an 8.6-metre trimaran with a beam of 2.8 metres, built in 2024 and equipped with official navigation permits for offshore sailing up to 12 nautical miles from the coast. Groups are limited to 10 participants for an intimate experience alongside the guide and vessel skipper; each trip runs for approximately 6 hours.

The pelagic season at Santoña runs mid-August through mid-November, precisely the window when post-breeding seabirds dispersing from their northern Atlantic and Arctic breeding grounds concentrate along the Cantabrian shelf edge during their southwestward migration. The continental shelf narrows dramatically off Cantabria, bringing the shelf break relatively close to the coast and funnelling migrating seabirds within reach of offshore boat trips. The Bay of Biscay is one of the most important post-breeding staging areas in Europe for the Critically Endangered Balearic Shearwater (Puffinus mauretanicus — approximately 15,000–20,000 birds globally), which congregates in large numbers in its waters from July through November alongside Cory's, Sooty, Great, and Manx Shearwaters. All four European skua species — Pomarine, Arctic, Long-tailed, and Great — pass through the Bay of Biscay in regular autumn migration, as do Sabine's Gull and Grey Phalarope. European Storm-Petrel and Northern Gannet are additional regular companions offshore.

Aves Cantábricas also organises separate estuary boat trips within the Marismas de Santoña, Victoria y Joyel Natural Park for wading bird and wildfowl observation — these are distinct products from the offshore marine seabird pelagic trips. The offshore pelagic programme targets only true open-water migrants using the Calidris to reach shelf-edge seabird concentrations. Contact Alejandro García directly to book a place on a scheduled pelagic departure.