We spent the morning today cruising the deep blue waters of the Gulf of California between the islands of Tortuga and San Marcos. Conditions were perfect for observation of marine mammals: light winds and calm seas, warm but not hot, and bright sunshine. For some time the seas were very quiet; we had a brief sighting of a sperm whale during breakfast and a bit later we had good looks at a dwarf sperm whale, a very rare but rather unspectacular creature.

After several hours of searching we spotted a blow in the distance, probably the sperm whale, and began to cruise toward it. Suddenly a large whale surfaced right beside us! We had not seen it approach at all, but it remained near the surface now and it soon became clear that it was a blue whale, the largest animal ever to live on earth. Blue whales are well known to inhabit the Gulf during the early spring but there have been only a few sightings of them this year, so we were very excited to see it.

And our excitement grew enormously when this whale repeatedly circled the Sea Lion and dove just under our stern, surfacing again only a few feet away, on the other side of the ship. We could clearly see the whole animal under the water, its pectoral flippers and flukes shimmering through the green sea. It remained with us for almost half an hour and then swam away as quickly and silently as it had appeared. It had taken some patience to find, but we had been treated to a truly exceptional blue whale sighting.