'I can promise you the trip of a lifetime." It was my first evening on board Searcher and the speaker was the vessel's captain, Art Taylor, a rugged 50-year-old Californian. Four times a year for the last 15 years, Art has been taking a maximum of 24 passengers on board his 95ft vessel on 12-day whale watching and nature tours around Mexico's Baja peninsula, at 800 miles one of the longest and narrowest in the world.
During that first briefing session, Art ran through the essentials. The accommodation would be comfortable - with air-conditioned cabins. The food would be plentiful, the crew skilled and knowledgeable. For those of us who wanted to see a desert environment, Baja California was sans pareil. On half a dozen occasions, we would be landing from skiffs on the mainland or on one of the islands and we would have a chance to hike through the wilderness, keeping a wary eye out for rattlesnakes, scorpions, tarantulas, centipedes and sandflies.
As for those of us who wanted above all to observe marine wildlife, we would, Art hoped, return home satisfied.
He ticked off the species we would be most likely to encounter. Seals and sea lions, dolphins, pelicans, ospreys, humpback whales . . .
"You may even get to see a blue whale," he said. "We usually do on these trips."
I have to admit, when I heard that last claim I was incredulous. As far as I knew, the blue whale, the largest creature ever to exist on the planet, was effectively extinct, its population driven to such low levels by decades of commercial whaling that it could never recover.
Was Art joking, I wondered?
Five days later, we had just finished lunch in the salon when we heard the captain's voice over the loudspeaker.
"Blue whale on the surface. Two hundred yards at one o'clock."
As I rushed to the bow, I heard a great swooshing noise. In the water just in front of the boat, I saw an immense blue-grey shape. The column of spray must have reached 30 or 40ft into the air, rising straight up like some gigantic geyser.
We stayed with that blue whale for three-quarters of an hour that afternoon. It spouted two or three times more as it moved slowly through the water ahead of us. Rob Nowajchik, Searcher's resident marine mammal expert and on-board lecturer, told us what was happening: "After three or four spouts, he'll be getting ready to dive."
I could see that the leviathan now seemed to be hunching its enormous back. The head was already under the surface and the dorsal fin had appeared.
"He's going to fluke!" Rob said.
A blue whale fluking at a distance of not much more than 100 yards is one of the most awe-inspiring sights I have ever witnessed. Ahead of us, the water boiled and churned and then, suddenly, we found ourselves once more looking at an empty ocean.
There is luck in this, of course. But there is also judgment. Experienced whale watchers look for the whale's footprints, unnaturally smooth and glassy patches of water caused by the upward pressure of the flukes on the water column. With clear seas and an animal the size of the blue whale, you can actually see the outline underwater long before it rises to the surface.
Still, as Searcher continued south, rounding the Cabo San Lucas and entering the Sea of Cortez, I found myself wondering whether that one sighting of a blue whale had been an accident. Seeing one specimen, however splendid, didn't mean that the species as a whole had been clawed back from extinction.
The Sea of Cortez, otherwise known as the Gulf of California, runs up on the inland side of the Baja California peninsula. Biologically, it is one of the richest bodies of water on the planet, supporting 900 species of marine vertebrates and 2,000 invertebrates. Searcher steamed north among some of the many islands that, collectively, have been designated a world heritage site. Around 4pm on Sunday April 1, we were off the northern end of San José island when we had a blue-whale experience that made that first afternoon's sighting seem like nothing more than the hors d'oeuvre. We found ourselves in the presence, not just of one blue whale but as many as 20.
At one point, a whale actually swam right under the boat. Its head emerged one side of the vessel while passengers were still leaning over the rail on the other side watching the tail.
"Must be a juvenile," Rob said, standing next to me. "It's not big enough for an adult."
I found myself uttering a quiet prayer of thanks. Here at least, I thought, in Mexico's Sea of Cortez, the blue whale must be breeding. If the species could bounce back here, maybe it could bounce back in other parts of the world as well.
During our time on the Sea of Cortez, we didn't just see blue whales. We saw humpbacks and sperm whales as well as fin and bryde's whales. The whole enchilada.
And the two days we spent with the grey whales in their lagoon breeding grounds on Baja's Pacific coast were, for many of those on board, as memorable as that magical afternoon we spent with the blue whales in the Sea of Cortez.
On our way south from San Diego, Searcher had encountered at various times at least 10 grey whales, heading north on their annual journey from the lagoons of Baja where they mate and breed, to their feeding grounds in the Bering Sea, 6,000 miles to the north off the coast of Alaska.
This is one of the world's most spectacular migrations. The grey whale may not be as large as the blue whale (around 40 or 50ft in length as opposed to 100), but it is nonetheless one of the great denizens of the deep. Hunted virtually to extinction in the 19th and 20th century, the grey whale has made an extraordinary recovery, and the population is now around 18,000.
Around 10am one morning, after waiting for the tide to rise, Searcher crossed the sandbar which separates San Ignacio lagoon from the open sea. Here each year, the grey whales come to calve, the warm waters of the lagoon providing an ideal nursery for their young who, as it were, find their feet here before accompanying their mothers on the long journey north.
Almost as soon as we had entered the lagoon, we could see whales spouting around us. The funnel of spray as a grey whale "blows" does not rise as high into the air as that of a blue whale, but it is still a dramatic sight. And the closer you get to them, the more remarkable these whales appear.
For a species that has absolutely no reason not to fear and loathe the human race, the grey whale seems remarkably forgiving. Indeed, one of the remarkable features of whale watching in San Ignacio lagoon is that quite often this seems to be a two-way process. You can be out on the lagoon with a local boatman in one of the licensed pangas when a grey whale, often with her calf, will push alongside the boat. They will raise their huge heads right over the side of the panga and you can find yourself, literally, eyeballing a 50-tonne monster, which could, if it so decided, send your frail craft to the bottom of the sea with one flick of its enormous tail.
I held out my hand to one animal as it approached us and felt the strange rubbery texture of the hide.
There seems to be no evidence that the whales object to this close contact and plenty of reason to suppose the opposite.
Our Mexican boatman that morning told us how a few years earlier, Mexico's then President Zedillo came to the lagoon with his wife and family. This was a crucial moment. The Japanese giant Mitsubishi was pressing very hard for permission to open a huge salt factory on the lagoon that could have threatened the very survival of the gray whale.
"The President and his wife and kids, they come out in my boat," Ernesto told us. "The President's wife, she kissed the whale right on its head that day. I saw it. I was there. So the president, when he saw his wife kissing the whale, he said 'Right. No more salt factory. We keep the lagoon just for the whales.' And he announced the end of the salt project that very day!"
This was not some apocryphal story. The Mitsubishi threat had been a real one. With an $80 million investment, the company hoped to generate annual revenues of $85 million. President Zedillo's intervention came in the nick of time. He left office the next day.
Whatever Mexico may have lost in terms of direct investment as a result of his brave decision, it has - I am sure - more than made up through the income generated by whale watching in Baja.
But the story doesn't end there. The international ban on commercial whaling, which has been in force since the mid-80s, is coming under increasing pressure. The battle between pro-whaling and anti-whaling nations was joined again in May this year in Alaska, when the International Whaling Commission held its annual meeting.
The Mexican government, proud of all that is has achieved in Baja, once more took the lead among nations determined to keep the ban in place. As a result, moves to end the moratorium on commercial whaling were defeated. As the importance of whale watching as an alternative to whale catching is now increasingly being recognised, we must hope that those countries which still ignore or subvert the ban - such as Japan and Norway - will finally realise that killing whales has no economic, moral or environmental justification.
Looking back at those 12 days on board Searcher off the coast of Baja California, I can't help thinking that Art Taylor's talk of a "trip of a lifetime" was amply justified. Eco-tourism is a term much misused. But in this particular case, I think we all of us felt that we were somehow helping to strike a blow that might in the long run - perhaps the very long run - restore the whales to their rightful place in the ocean.