In Yucatan itself, though, we were the only ones going our own way. The tour buses loaded up and headed off to Cancun, home of the all-inclusive resort hotels, while the taxi we'd arranged headed in the other direction to a travellers' hang-out called Playa del Carmen.
And thus it was that I found myself on a Mexican beach at 5am, watching the sunrise with my wife Suzanne, our children Thomas and Rhena, and our friends and their two children. Around us a smattering of tipsy, drowsy overlanders were reaching that "let's go back to my place for breakfast" stage in their relationships.
It isn't easy trying to perpetuate a travelling life with young children. In the seven ages of man, we've done the mewling, puking and backpacking, but now that we have excess baggage of the noisy variety we'd didn't see our future holidaymaking cooped up in a rented cottage in Cornwall.
Like our friends, we belong to a generation that was able to take advantage of cheap, long-haul flights, acquiring an addiction to adventure that is hard to kick. In the past we've done Bali, Sri Lanka, New Zealand and Morocco with the children ( aged between four and six), but none of us had ever been to Latin America.
Mexico sounded like a suitable blend of exoticism and tourism, but the brochures were stuffed with all-inclusives - not our style - and a family fortnight would have cost us upwards of pounds 4,500. A quick ransack of the internet, though, produced flight-onlys for pounds 249 each, and a variety of small hotels in Playa at around pounds 45 per night, making a total that came in at well under half the brochure prices - and confirming my increasing conviction that the web is invaluable for the ex-traveller who feels frustrated by what the average package holiday has to offer.
Playa del Carmen may have been too small-time to raise a tour operator's eyebrow, but it suited us to a T. An endearing mix of slightly ramshackle thatched cabanas, music bars and small, smart owner-run hotels along a crescent of sand, with a proper town at one end of its main pedestrian avenue, and designer, ochre-walled boutiques in wood, wrought iron and lapis lazuli at the other. Cuban bands played in beachfront bars to an audience that was mainly seasoned, fashionable young Europeans. Stocky Mexicans in sombreros sat on the kerb playing the guitar, and occasionally suggested that you might want to visit their shop, amigo.
This was a different world to Cancun, to which we made an early pilgrimage. The 10-mile strip was a sort of Vegas-by-the-sea, a mecca of sun and consumption, where huge sound systems made the sand bounce. It was swilling with splodgy Americans moving between the Hard Rock, Planet Hollywood and the Rainforest Cafe; prices were suitably sophisticated, and Mexico barely peeped round the sides.
The other main destination in our neighbourhood was directly across the water from Playa, and from a distance Cozumel sent out confusing messages. Cruise ships came and went, it was reputed to have some of the best diving in the world, it had the charisma of an island, and yet - what were those tower blocks doing on the horizon?
Initially, we'd thought of spending a couple of nights on Cozumel, but the ferry from Playa disembarked us among a crowd of ecstatic dog-collared Americans - "pilgrims of Mary" according to their name-badges - who, judging by their girth, lived a regime of praise the Lord and pass the doughnuts. A shop on the quay sold T-shirts with "10 lies you're likely to hear on Cozumel", which included "no, the free jeep rental has nothing to do with timeshare". It wasn't an auspicious start.
The town seemed ... worn out. Every other day it was flooded by cruise ship passengers who descended on the barn-like jewellery stores like a tidal wave. We hightailed it by taxi down to the Chankanab National Park, past a dive centre with a sign which read "make new friends - and then eat them". Happily, the sea at Chankanab was gentle and crystalline, and rentable lifejackets helped the children overcome their fear of snorkelling - and the surprise of discovering they were sharing the water with quite big fish. But actually staying on Cozumel got the thumbs down.
Now that we'd established what lay to our north and east, we started to make day trips south by long-distance bus - sweaty seats and smelling suspiciously of disinfectant, but frequent and cheap.
You wouldn't come to this part of Yucatan for the scenery, though. The coastal highway grumbled on through a flat, uninterrupted tropical tangle, although it concealed several fine collections of Mayan ruins and even more cenotes - freshwater lakes fed by underground rivers and often half-hidden in limestone caves.
The shoreline is interrupted occasionally by what looked like Rorschach inkblots of azure blue - creeks created by those underground rivers breaking through to the sea, three of which have been turned into tourist attractions: Xcaret, Xelha and Xpuha. We settled for Xelha, on the grounds that Xcaret had something of a reputation as a Mexican Disney, and Xpuha was new and an unknown quantity.
Making the choice is not done lightly as these attractions are far from cheap. At Xelha, the main interest was floating downriver through mangroves into the open creek and swimming with the dolphins, which would have cost extra.
These attractions were well organised, but they were aimed at the Cancun tour buses; for us, finding our own watering holes was more exciting. We hired two VW beetles (still made in their original form in Mexico), and discovered the first cenote cradled in a massive cave partly lit by a natural blowhole up through the rock. Given that the sun never reached it, the water was surprisingly warm, but whenever I stood still little fish took an alarming interest in a blister on my foot.
Further south we found another, but this one was completely open-air, surrounded by thick vegetation heavy with iguanas. The water was soupy green with algae, but it, too, was a lot of fun.
Yucatan's Mayan ruins were harder to manage with the children. At Tulum, the palaces and temples are scattered like grey dice along the sward that backed a cliffy shore, and we could leave the children on the sand while we did a bit of cultural tourism. But at Coba, inland, the ruins were on a far grander scale, distributed through 30 sq miles of jungle - too ambitious for little legs in the heat. Half the party adjourned to a cafe by the lake to eat tacos and listen to the cafe owner explain how he fed raw chicken to the lake's crocodile every morning.
We did, of course, have difficult moments. Thomas got an ear infection and we had to wake up the doctor in the 24-hour clinic for a consultation in broken Spanish, interrupted by a demented American searching for his wife. A couple of times a restaurant menu was too unrecognisable for the children - a situation rescued by ordering bean soup, draining away the liquid and claiming the result as baked beans.
But we crossed a sort of threshold, too. Returning from the Tulum trip, ploughing through the hot night in a long-distance bus amid a crush of bodies, we realised that the children had accepted what many adults would not; they were participating in a true travel experience, and showing every sign of enjoying it.
British visitors do not need visas. High season for tourism is late December through to April, with heavier rainfall between May and November. Now is a good time of year for special offers, with charter flights at around pounds 399 - contact Flightline (tel: 01702 470757 or www.flightline.co.uk). Scheduled airline fares start from around pounds 550, and Kuoni has 14 nights at an all-inclusive resort in Cancun from pounds 829 per person, departing 19 July.
WHERE TO STAY
Find out about accommodation from the internet (www.cancunsouth.com/PlayaDelCarmen.htm) which has several hotel links. We stayed at Treetops hotel (www.treetopshotel.com) and then at the Hotel Paradise (www.hotel-paradise.com), which was a particularly good deal for families at pounds 42 for a room. The most interesting of Playa's small hotels was the Baal Nah Kah, originally built out of native materials as a private residence (www.turqreef.com).
The best guide to Yucatan is The Moon Handbook, pounds 11.99, although it is out of stock in the UK. Insight Pocket Guide: Yucatan Peninsular, pounds 6.99, has good maps.