While sailing the Sea of Cortez, waiting for sperm whales to appear, I read “;In the Heart of the Sea: The Tragedy of the Whaleship Essex.”; This book by Nathaniel Philbrick gives a contemporary version of what happened when a male sperm whale, judged by the whalers to be 85 feet long, rammed and sank a Nantucket, Mass.-based whaling ship in 1820.

The story is one heartbreak after another, from the misery of life aboard a whaling ship, to the slaughter of those colossal animals (the largest sperm whales seen today are only 65 feet long), to the irrational fear of Tahitians, which caused the men to steer away from the nearby Society Islands, to the straw-drawing cannibalism in the starving men's lifeboat.

An American poet in 1976 called the Essex disaster “;a past we forget that we need to know.”; Well, I didn't need to know it, I thought, after I finished the book. The human and animal suffering in the story gave me a stomachache.

Days later, though, as I sailed up the Canal de Ballenas, the Channel of Whales, watching for whale spouts, the reason for remembering this dark slice of American history became clear. Unless we know how bad it was in the past, we can't realize how good it is in the present.

Today when humans look for whales, we do it in comfortable boats with safety equipment the Essex men couldn't have imagined.

And since for decades our purpose has been either appreciation or study, sperm whales don't fear boats.

At least not the sperm whales in the Sea of Cortez (aka the Gulf of California). I know this because when one spotted our 37-foot sailboat, it swam toward us and then dived beneath, giving Craig and me the thrill of a lifetime.

We first saw two sperm whale pairs floating on the surface looking like massive brown logs with bumps. The bumps, called knuckles, run down the middle of the sperm whale back to the tail. The whales were easy to spot because they rested on the surface catching their breath in blow after blow after blow.

Sperm whales can dive to astonishing depths (the record is 10,500 feet) for up to two hours, hunting their favorite food, squid. When a whale comes up for air, its first breath is loud and explosive, followed by 30 to 40 quieter breaths. Since the sperm whale blowhole is at the tip of the snout and left of center, the blow is forward and left, a telltale sign for identifying the species.

After the whales caught their breath, one poked its rectangular head up to check us out, slightly opening its narrow lower jaw. I saw this clearly through binoculars and got so excited I nearly fell over the side. Then down they all went, their flukes sinking in slow, graceful dives.

The next day, as we sailed along at 3 mph, we came upon another pod of sperm whales catching up on oxygen. The closest whale peeked at us, turned and then casually swam under the boat. While I was reading the Essex book. I wondered whether I'd be scared if an adult sperm whale came close to boat. I was not. Nor was the whale.

I'm glad I read Philbrick's book before I saw my first sperm whales. Knowing the details of that era and the disaster of the Essex, which Herman Melville used as a basis for “;Moby-Dick,”; helped me see and enjoy the bright side: It's over.

Today sperm whales and I watch each other in peace.

Susan Scott can be reached at www.susanscott.net.