A baby sea lion peers at me through big, brown eyes, its whiskers tickling my face. With a twirl of his flippers, he somersaults backwards.
I follow suit, and soon we are pirouetting together under the sea. It is a brilliant, breathtaking moment — or, just another day when you're in the Galapagos.
The islands, 600 miles off the coast of Ecuador, are famous for incredible flora and fauna. They were the trigger that inspired Charles Darwin's theory of evolution — and, in case you missed it — this is the 150th anniversary of his book On The Origin of Species and the 200th anniversary of his birth.
The original Beagle on which Darwin sailed was a 'coffin' brig — they were easily sunk — with no space and limited rations. My berth is slightly different: I am one of 11 tourists on a 105ft, luxury yacht.
We board at Santa Cruz one of the Galapagos Islands, and are swiftly off on our first expedition.
It is to the Charles Darwin Foundation (CDF) to see Lonesome George, the sole surviving giant tortoise from Pinta Island.
But George is hiding, so, instead, our guide Daniel points to the next enclosure. This tortoise, nicknamed Super Diego after he was discovered in San Diego Zoo, saved the Espanola form. The species had dwindled to 14 before he was discovered; he was introduced to the females and sired a new dynasty, now thousands strong.
We go to bed in Santa Cruz. For more for Overnight, our Beagle repositions, and we awake in a deserted bay off Floreana. I go on deck at the first pinpricks of light. It is silent but for the odd sea lion bark (a bit like a goat being throttled). At 7.30am, the bell is rung for breakfast, and Daniel reminds us of the day's schedule.
The sightseeing starts before we've left the table. As we devour fresh papaya, French toast and Ecuadorian coffee, a raft of penguin swim past, stubby wings flapping.
The dinghy drops us on a jetty, which is covered in basking marine iguanas. The 'infernal imps' as Darwin called them are around one metre long, their slack, scaly bodies mottled in crimson, black and green, with crenellated heads and long toenails.
Like all the endemic creatures they are tame, not having evolved to fear mankind. He waddles, clumsy on the land, then vanishes underwater sleek as a dart.
While many of the islands are stark stretches of basaltic rock, Floreana has a verdant interior and we trek into the hills to an artisan spring. A rare source of drinking water, it was used in the 17th century by pirates as they lay in wait for the Spanish galleons heading home with Inca gold.
Another draw for the pirates, and later the whalers, were Floreana's giant tortoises: able to survive for a year without water, they provided fresh meat for long sea crossings.
They introduced goats to several islands as another food source. Released into the wild, the goats destroyed the native ecosystem, eating bird and tortoise eggs. The Floreana tortoise is now extinct. brilliant ideas visit com The hike down from the pirates' cave is hot, so it's a relief to return to the boat and snorkel. After lunch, we land again, at the northern tip of Floreana, on a white sand 'flour' beach. It is covered in wonky tyre tracks, where marine turtles have come ashore to lay. Overhead, a lone frigate bird wheels back and forth on the lookout for hatchlings, his 2.2lb body weight spread over a 7ft wingspan.
Many of the birds on the islands are critically endangered. Along with Darwin's great-great grandson, Randal Keynes, the CDF is also launching a desperate attempt to save the Floreana mockingbird — the bird that made Darwin wonder if wildlife could have developed differently on different islands.
The Floreana mockingbird has been wiped out on its namesake island, but around 100 breeding pairs have been found on two satellite islands, making it the rarest bird in the world..
On Espanola, we walk up jagged cliffs where tame Nazca Boobies are nesting only feet from the path.
Then it's San Cristobal. We hike for four hours through an ethereal landscape where acres of palo santo incense trees are hung with moss, and the giant tortoises amble out of the mist. On the shore, sea lions play on a perfect rip curl break: bodysurfing through the wave.
Once on Santa Fe, we traverse volcanic lava, dizzy in the heat, the wildlife mostly land iguana and prickly pear cacti. In contrast, on Plaza Sur, we gaze at the cliffs heaving with life: blue-footed boobies stand on guano-stained boulders.
On Seymour Norte, the magnificent frigate birds are courting, the males inflating red throat sacs and calling to the females.
Towards the end of our trip, we visit Bartolome, famous as the place where Russell Crowe was shot in the film Master And Commander. We climb to the tip of the island. On one side is Pinnacle Rock, the spiky remnant of a volcanic peak which rises out of the water. On the other, two white sand beaches arc towards one another as the waist of the island.
Spread before us, the Galapagos are beautiful, and a thought-provoking glimpse into the origins of life. There is the sense of timelessness in this remarkable, real-life wonderland.
THE Ultimate Travel Company offers the classic ten-day Galapagos experience from £3,850pp. Price includes two-nights' stay in Quito, Ecuador, seven nights' full board on the Beagle, all activities, visits ashore, return flights and private transfers, ex-London.
WEB WISDOM For more brilliant destination ideas for adventure travel, visit thisistravel.com
Original article published in The Daily Mail, in February, 2010