During the summer, 40-ton acrobats put on a show off the coast of San Luis Obispo County. They dive, leap into the air, roll on their backs and blow great clouds of spray into the air.
When people think of whale watching, they usually picture gray whales, which pass through the area as they migrate to and from Alaska and Baja every winter and spring.
But the summer is also a good time to watch humpback whales as they take up residence off the Central Coast. Humpback watching has been particularly good this summer.
David Butler, a captain with Sub Sea Tours and Kayaks in Morro Bay, recently led a trip that saw more than 20 of the behemoths. That, coupled with dolphins, seals and other marine life encountered that day, made the trip one of the best wildlife viewing experiences Butler has had.
On Tuesday morning — the day of summer solstice — Butler nosed the Dos Osos whale watching catamaran with about 20 tourists aboard past Morro Rock and into the open ocean. The destination was Church Rock, an undersea promontory about five miles offshore that is a favorite hangout of the whales.
“We spend a lot of time in that area,” Butler explained. “It’s kind of our hub.”
Everyone aboard spent the trip peering into the mist, looking for whale spouts. About an hour into the trip, the first pair of whales was spotted.
Adult humpbacks typically reach about 50 feet in length and weigh from 25 to 40 tons. Their black backs with namesake humps were readily visible as they swam along the surface.
For more than an hour, the Dos Osos loitered around the whales. In all, about 10 individuals and a variety of whale behavior were observed as the passengers busily snapped pictures and Butler described what was going on.
Unlike gray whales, which migrate through the area, humpbacks linger here from May to October. They are attracted by the area’s nutrient-rich waters that produce the krill and baitfish they feed on.
The flukes of their broad, barnacle-encrusted tails came out of the water as they dived to feed. Powerful strokes of their tails left calm spots on the surface called footprints or tail slicks.
When not diving or under the water, the humpbacks float on the surface and rest, a phenomenon given the descriptive name of logging. Their rest is punctuated by large, explosive exhalations that send spouts of mist into the air.
On this trip, none of the whales performed their most exciting acrobatic feat, breaching. This is when a whales surges out of the water and lands on its back with a huge splash. There were also no “friendlies,” a name given to a few whales that approach and sometimes swim under boats out of curiosity.
The humpback whales off Morro Bay are part of the Central Coast population, about 1,000 animals that summer between San Francisco and Point Conception, said Kevin Winfield, owner of Sub Sea Tours. The whales spend the winter mating in the warmer waters off Central America.
Other species of whales — including blue whales, Earth’s largest living creature — are also seen, but during the summer, the humpbacks are the whale watcher’s mainstay.
Butler estimates he is about 90 percent successful in finding whales. On those trips when no whales are seen, passengers are given vouchers for another trip.
For more information about whale watching, go to www.morrobay.org.