Whale watchers and marine biologists got an especially rare treat last week when a pod of two dozen Baird's beaked whales surfaced near a whale-watching boat off the coast of Monterey, and stayed long enough to be captured on drone video.

The typically deep-water whales, which are able to stay well below the ocean's surface for up to an hour and rarely travel in shallow coastal waters, swam along the surface in a tight row for around eight minutes last Wednesday, as SFGate reports. And the pod, which included 24 adults and three calfs, dove near the Monterey Bay Whale Watch vessel for about 25 minutes in total. As marine biologist Nancy Black tells SFGate, "This is the largest group of beaked whales I have seen over the last 30 years and I have only seen this species of whale about 10 times in my life."

Below is the extraordinary video taken of the group aboard the boat.

Baird's beaked whales have long, dolphin-like beaks, and they are the largest beaked whale species, growing up to 42 feet long. They are also the only beaked species found in the northern Pacific. The species was named for Spencer F. Baird, who was a well-known naturalist of the late 1800s and a secretary of the Smithsonian Institution, as the American Cetacean Society explains. Not only do the whales dive to depths of 3,000 feet, feeding on deep-water fish and squid, but they don't have dramatic blows of air like other whale species and therefore aren't often detected by ships when they do surface.

The Marin County-based Marine Mammal Center got to examine its first Baird's beaked whale in its 41-year-history back in 2016 after one was killed by a ship strike and washed ashore near Point Reyes.

As Black tells SFGate, "The beaked whale family of whales is among the least studied and most mysterious of all whales."

Multiple species of whales make northward migrations along the California coast at different times between spring and summer, and Monterey is often one of the best vantage points for spotting them. Gray whales, which make some of the earliest migrations, have been turning up dead in alarming numbers this season, prompting a federal investigation by the National Oceanic and Atmospheric Administration. A total of 70 whales have washed ashore on the western coast of the US this year, and the cause is believed primarily to be malnutrition due to lack of food.

Related: It's Officially Whale-Spotting Season In San Francisco Bay