The prow of the Blanca Beatriz plunged into another wave, and the strip of land I had been yearning for shot out of sight above the boat's battered canvas awning.
I had already been on this creaking Mexican launch for half an hour, squeezed on a bench next to an alarmingly pregnant woman, and the island was scarcely in sight.
What in the world was I doing here: a mom from suburbia, heading for Isla Mujeres, a Mexican island that few had ever heard of and fewer still had visited?
I looked down the length of the rolling deck to where my son Hugh was sitting. He sat quietly, for a tiny Mexican girl was sleeping against him, lulled by the heaving rhythm of the boat. I saw that he had put his arm around her protectively.
It had all started because Hugh wanted to spend every minute of his January college break in the sun, as far as possible from Boston's bleak winter. My husband had arranged the last part of the week to coincide with a business trip to Mexico City and a visit with old friends there; but the first half was open. "Why don't you two go to Mexico first?" he suggested. "Find a quiet beach where you can get some sun, and meet me later in Mexico City."
What a fine idea! Just our older son and me vacationing alone. I missed his good company and conversation now that he was away at college. It would be nice to have him all to myself for a few days and catch up.
We booked an economical tour package to Isla Mujeres, five miles off the coast of the Yucatn Peninsula. The name - "Island of Women" - added to its appeal for Hugh.
When our plane landed in Cancn, a full-blown "norther" was in progress. It was during just such a storm in 1517 that Isla Mujeres was discovered by Hernndez de Crdoba when his fleet blew up against the island.
We hailed a vintage taxi and rocketed down the highway toward Puerto Jurez, where we were to take the launch to Isla Mujeres. The stormy sea looked menacing, particularly when I saw the condition of the Blanca Beatriz, with her garishly striped awning and peeling paint.
As Hugh unloaded our bags, I started a futile debate with the taxi driver about accepting the tour company's voucher as payment.
The boat seemed ready to depart without us. Then, suddenly, Hugh produced a handful of pesos from his pocket and negotiated the taxi fare in Spanish. "Let's go!" he said, hoisting the bags and leading the way to the launch.
"No more room," a sailor signaled as we raced down the pier. Hugh swung one leg across the water to the boat and planted it firmly on the deck. He tossed his bags on board, reached for mine, and then pulled me up after him. Making sure I was securely wedged between the very pregnant woman and a bulkhead, Hugh then found his own cramped space across the deck and gave me a wave.
An hour later, the low coastline of Isla Mujeres, with its row of small pastel buildings, appeared above the choppy water.
In the confusion of disembarking I'd forgotten our family's cardinal rule to always count our bags, but Hugh remembered and hurried back to retrieve the one I'd left behind.
And it was also Hugh who remembered to order only bottled drinks and avoid ice cubes when we sat down to dinner in the hotel later that evening. He ordered for us in Spanish, and I gratefully toasted my protective son, who had maneuvered us safely through a harrowing day.
In the morning, at breakfast in the glass-walled dining room, we had our first bright view of the water surrounding our hotel. Its sparkling clarity explained the name given the island by the Mayans: Zazil-Ha - Luminous Waters.
We planned our day, a moped tour, guaranteed by the English translation in the guidebook to be "the cheapest and funniest way to go exploring."
Hugh dealt with the business of renting a Honda-for-two, and after being sure I knew how to adhere firmly to the pillion and hold onto his waist, we were off in a blur of blue.
"Where did you learn to drive one of these?" I called to the wind.
And, by the way, where did he learn all the other things that had unexpectedly adjusted the balance in our relationship to favor his skills over mine? I was the mother. I was the one who was taking my son on holiday, wasn't I? We went over a washboard section of road, and I hugged his waist tighter, only partly to hang on.
Where, and from whom, had he acquired the savoir-faire to deal so easily with the small emergencies of travel, and in foreign tongues and currencies? I could name steps along the way: his first flight when he was not yet 2 and we were moving to Spain; his earliest words in Spanish, his subsequent adjustment to English, French, and American schools; his consistent reliability.
But when did he become an adult?
When the road ended at the southern tip of the island, we took a footpath to see the remains of the 1,000-year-old temple dedicated to the Mayan goddess of fertility and basket-weaving.
In this tiny stone building, women once made offerings of fruit and copal incense, praying for safe deliverance in childbirth. Thus was the island named by the Spaniards Isla Mujeres.
I offered my own small prayer of thanks for a child.
That night we went to one of the livelier restaurants on the island for a sumptuous feast of lobsters drenched in butter. One of us overindulged, and I was glad that a mother's comforting was still needed. I reflected on our changing roles - and on the roles that probably would never change.
Today, a decade later, the hotel where we stayed is abandoned, and a hurricane has blown the last crumbling remnants of the Mayan temple to its final rest under the sea.
The other night I talked to Hugh in London, where he and his family now live. I asked him what he remembered about our visit to Isla Mujeres.
"I remember eating too much," he said, laughing.
"It was the lobsters we ate that night," I added.
"No, it wasn't, it was the seviche at noon, don't you remember?"
Well, no, I don't remember the seviche. And it's clear that he doesn't recall the trip as more than a tropical break between winter semesters.
But I remember it as a more complex transition: it was a passage we made together toward acknowledging his manhood.