Blue whale (Balaenoptera musculus). The silhouette of a blue whale tail in bright afternoon light. Gulf of California.

Blue whale (Balaenoptera musculus). A typically view of a very relaxed blue whale tail as it begins a shallow dive. Gulf of California.

A diving blue whale (Balaenoptera musculus) tail and dorsal fin. Gulf of California (rr)

Blue whale (Balaenoptera musculus). A blue whale tail as it leaves the water prior to diving. Gulf of California.

Blue whale (Balaenoptera musculus). The blows of two blue whales, an adult and a juvenile. Gulf of California.

Blue whale (Balaenoptera musculus). The tail of a blue whale beneath rugged cliffs. Gulf of California.

Blue whale (Balaenoptera musculus). In the early light and silky sea a gentle blue whale barely makes a ripple. Gulf of California.

Blue whale (Balaenoptera musculus). Tourists watch the sedate progress of a blue whale as it circles their boat, the animal is feeding. Gulf of California.

A curious Brydes whale (Balaenoptera edeni) swims alongside a boat. Gulf of California.

Blue whale (Balaenoptera musculus). A blue whale showing the typical mottled skin colouring. Gulf of California.

Close up of a blue whales massive blow (Balaenoptera musculus). H

Blue whale (balaenoptera musculus). A blue whale tail. Gulf of California.

Blue Whale (Balaenoptera musculus). Tail Fluke above the surface before diving, Gulf of California, Mexico.

Blue Whale (Balaenoptera musculus). Looking along back-bone to blow hole, Gulf of California, Mexico.

Blue Whale (Balaenoptera musculus). Tail Fluke above the surface before diving, Gulf of California, Mexico.

Blue Whale (Balaenoptera musculus) fluke-up dive in the middle Gulf of California (Sea of Cortez), Mexico.

Blue Whale (Balaenoptera musculus). Looking along back-bone to blow hole, Gulf of California, Mexico.

Blue Whale, Balaenoptera musculus, surfacing off the Azores Islands

Blue whale (Balaenoptera musculus) surfacing, Azores, Atlantic Ocean

Blue Whale (Balaenoptera musculus) fluke-up dive at sunset in the offshore waters of Santa Monica Bay, California, USA.

Blue Whale (Balaenoptera musculus) Adult fluke-up dive. Gulf of California (Sea of Cortez), Mexico.

Two Blue whales, (Balaenoptera musculus), diving together, Monterey Bay, California, USA

Blue whale, (Balaenoptera musculus), fluking up sequence 2/3, Monterey Bay, California, USA

Blue Whale (Balaenoptera musculus) Mother and calf fluke-up dive in the Gulf of California (Sea of Cortez), Mexico.

Three blue whales move through their protected territory.

Blue whale (Balaenoptera musculus). A blue whale footprint. Gulf of California.