Imagine spending the afternoon on a boat, the ocean spray hitting your face, the sun warming your shoulders, when suddenly, a magnificent blue whale leaps from the water.

The blue whale, or Balaenoptera musculus, is one of the Earth’s longest-lived animals (80-90 year lifespan) and is the largest animal known to have ever existed. Blue whales are long and slender, with a tapered body and a small dorsal fin. But measuring in at up to 100 feet in length and more than 200 tons (400,000 pounds) these are truly creatures to be reckoned with.

Blue whales live in every ocean of the world and there are several separate populations: the Northern Hemisphere, Southern Hemisphere, Atlantic, and Pacific populations. They spend the summers in food-filled polar waters and then make a long migration towards the equator as winter arrives.

While blue whales occasionally live in pods, they travel more often alone or in pairs. These graceful swimmers glide through the ocean at around 5 miles per hour, but can reach speeds up to 20 or 30 miles per hour when threatened.

Once they reach their wintering areas, the mating season begins and lasts from late fall to very early spring. Not much is known about the mating habits of blue whales. How they attract partners and whether males mate with multiple females or just one is all unknown. Blue whales reach maturity between six to ten years of age and females give birth every two to three years in the same summer waters where they mate.

Baby blue whales, called calves, remain in their mother’s womb for about a year and are born tail first. A newborn blue whale weighs two to three tons (the size of two to three minivans) and can be up to 25 feet long. Within seven months, the calf doubles in size, gaining an average of 200 pounds a day. Remarkably, nothing but mother’s milk fuels this amazing growth.

Belonging to the mammal class, blue whales are air breathers. They have two blowholes and breathe voluntarily, meaning they decide when to take a breath, unlike humans, who breathe involuntarily. Blue whales can hold their breath for 10-20 minutes and dive up to 1,500 feet; however they usually don’t go deeper than the 300 foot depth preferred by their prey.

The blue whale’s food source is primarily krill, a small, shrimp-like creature found in every ocean. It may seem amazing that the world’s largest creature lives and grows on something so small, but a blue whale eats about 40 million krill a day during winter feeding. This critical diet permits the whales to build up their fat reserves and energy for the long trek south and gives the females the ability to feed their young.

Along with humpback whales and gray whales, blue whales are baleen whales. They get their name by the way that they feed; using baleen plates instead of teeth to filter small particles of food from the water. Made of keratin, the same material as human hair and fingernails, baleen looks like a giant comb covered with tiny hairs to help trap food. Blue whales are “gulpers” and can expand their throats to take in up to 50 tons of water in one gulp. The whales force the water out through the baleen, trapping the krill inside.

Perhaps one of the most unique qualities of blue whales is their “song.” In addition to many other achievements, blue whales are the loudest animals on earth. They emit a low frequency (far below human hearing) rumbling sound that can travel thousands of miles through the water. Studies have shown that whales use these sounds for a variety of purposes: to navigate, find food, communicate, and possibly as a part of mating. Despite everything we suspect we know about whale songs, there is still something about it that remains beautiful and deeply mysterious.

The blue whale gets its name from the true blue it appears under water; but once at the surface, its skin is more of a bluish-grey. Like other whales, blue whales briefly leave the water from time to time. There are many different names for the different ways a whale breaks the surface of the sea; some of the more common are breaching or cresting (when the whale leaps out of the water), spy hopping (when a whale vertically pokes its head out of the water), and lobtailing or slapping (when a whale raises its tail out of the water and slaps it on the surface). The chance to see these activities is a large part of what inspires people to go whale watching.

Unfortunately for those watchers, blue whales are endangered and only a fraction of the global population remains. They are considered one of the most rare and most endangered great whales. Protected from the 19th-century Captain Ahabs of the world by its sheer size, blue whales didn’t become a target of whalers until the 20th century when inventions like the harpoon gun and steam ships made hunting for them feasible. Blue whales were hunted almost to extinction until they were protected in 1967. Even after this protection, fleets from the former Soviet Union continued to hunt blue whales. Tens of thousands of blue whales were killed in single seasons.

Today, no blue whales remain off the coast of Japan, in the Gulf of Alaska, or along the southern Bering Sea, and only a few hundred are thought to live in Antarctic waters. Only the Northern Pacific population off the coast of California has shown any growth, but currently numbers only around 2,000 whales.

Whale watching can be done from private boats or through one of the many companies that offer whale-watching tours. Each year, millions of people around the world flock to various coasts to see if they can spot whales.

For blue whale watching, the peak season is from late spring to early fall, when the whales make their yearly migration. In the United States, the most popular place to whale watch is off the coast of California.

In Big Sur, whales can be seen from the shore on road turnouts and Monterey Bay Whale Watch offers tours.

Santa Cruz, Long Beach, and San Diego have large whale-watching industries.

Whales can also be viewed from San Francisco, including from the Point Reyes National Seashore.

Santa Cruz: Santa Cruz Whale Watching (http://www.santacruzwhalewatching.com/whales.html)

Long Beach: Harbor Breeze Cruises (http://www.2seewhales.com/)

San Diego: San Diego Whale Watch (http://www.sdwhalewatch.com/whale-watching/)

While they can’t guarantee whale sightings, most trips are narrated by certified marine biologists and the abundance of other wildlife, both in and out of the water, won’t disappoint.

If you’re looking to fit whale watching into a California national park trip, Channel Islands National Park is the place to be. Island Packers Cruises explores all five islands and conducts whale-watching tours. Anyone spending a day or two camping on the islands might even be lucky enough to spot whales from the shore.

Want to check out a national park and some whales at the same time? Be on the lookout for the upcoming “Best Parks for Whale Watching” round-up.

Go Whale Watching—

If Haley has inspired you to watch some whales yourself, now is the time to plan for a 2013 whale watching expedition. Join us this coming Sunday November 25, 2012 for Haley's roundup of great national park whale watching opportunities. She'll have a year-long calendar of places to visit and species to watch no matter the season.