Ambergris Caye or Isla Mujeres?

Isla Mujeres has the better beach. Playa Norte's soft white sand slopes so gently that you can wade a long way out with the water barely at your waist. It also faces west, so you can watch the sun set over the bay.

Ambergris Caye's sea is just as warm and turquoise, but the shore is a narrow band of sand with seagrass close in, so most people swim from the end of a dock. The nicer sand is north of San Pedro and in the still shallows of Secret Beach on the lagoon side. On both islands seaweed can wash up on the shore facing the open sea in the warmer months.

Food is similar on both islands, mostly fresh seafood and lobster in season, and neither is worth the trip for food alone. The difference is in the cooking. Ambergris Caye serves Belizean stew chicken with rice and beans, fry jacks at breakfast and Belikin beer, plus some candlelit dining rooms in the northern resorts.

Isla Mujeres cooks the Yucatecan way. Its speciality is tikin xic, fish grilled in achiote and sour orange, and the best value is at the market loncherías. For more variety you can cross to Cancun.

Neither island has much in the way of sights, and on both you go to the mainland for serious Maya ruins. Isla Mujeres has slightly more to see on land. There is the clifftop shrine to Ixchel at Punta Sur with its sculpture garden, the overgrown Hacienda Mundaca, and an underwater sculpture museum that you visit with a snorkel.

On Ambergris Caye the main pleasure is strolling past San Pedro's painted wooden houses. The Maya remains at Marco Gonzalez and Bacalar Chico are low mounds, more interesting for their history than to look at.

Evenings last longer on Ambergris Caye. San Pedro has beach and overwater bars that fill at sunset and a few dance spots that keep going past midnight. The soundtrack is reggae and punta, and the bars' weekly rituals soon become part of a stay.

Isla Mujeres is gentler. You start with drinks on Playa Norte and finish on the terraces and in the open-fronted bars of the pedestrian streets. Real clubbing means Cancun, and the last ferry back puts a limit on that.

This is where Ambergris Caye pulls well ahead. The barrier reef sits a few hundred metres offshore. Hol Chan's coral gardens and Shark Ray Alley are a short ride away, and divers can go out to Turneffe and the Great Blue Hole. On the lagoon side there are mangrove flats known for bonefish and tarpon, and Bacalar Chico in the north adds birdlife.

Isla Mujeres has one great natural draw, swimming with whale sharks in summer, and it only happens for part of the year. Beyond that there are the seabirds of Isla Contoy and snorkelling at Manchones. Neither island has any hiking to speak of.

Neither island is a base for many day trips, but Ambergris Caye's outings are easier to fit into a day. Caye Caulker is about 45 minutes away by water taxi, an easy island-hop to sand streets and an even slower pace. Organised trips also cross to the Maya sites. Altun Ha's restored plazas are the closest, and on the Lamanai trip the boat ride up the New River through the jungle makes the journey part of the day out.

From Isla Mujeres the ferry ride is short, but a day on the mainland still takes some effort. Cancun's Maya museum and the small ruins of El Rey are the easiest outings, and Puerto Morelos and Playa del Carmen are about an hour further down the coast. The bigger prizes are further away. Chichén Itzá, Tulum and colonial Valladolid are better known than anything you can reach from Belize, but each one means a long organised day of two and a half hours or more each way.

Isla Mujeres is better for younger children. Playa Norte's waveless shallows feel safe, children love the turtle sanctuary where hatchlings are raised, and the snorkel park near Punta Sur has zip lines for older children. You will need to plan around the lack of shade on the beach.

Ambergris Caye also has calm, warm water, and English as the everyday language makes things easy. Still, its seagrass and dock swimming are awkward for toddlers. It suits families with children old enough to snorkel with turtles at Hol Chan, ideally based at a resort with a pool.

Isla Mujeres is much simpler. The ferry dock, the town and Playa Norte are all within a few minutes' walk, a single coast road runs to Punta Sur, and Cancun is about 20 minutes away by ferry.

Ambergris Caye is more spread out. San Pedro itself is walkable, but the resorts stretch north along a long, narrow road, so you rely on golf carts and water taxis, and there are no buses. Just getting there takes a short flight or a long boat ride from Belize City.

Isla Mujeres has a bit more to browse, and it feels more like a market. Its pedestrian streets sell silver, embroidered dresses, hammocks and Huichol beadwork, and haggling is expected.

Front Street in San Pedro is more about edible souvenirs such as hot sauce, Belizean coffee, chocolate and rum, plus carved hardwood bowls and a few small galleries. Neither island is worth planning a trip around for shopping.

Isla Mujeres is easier on the wallet. Its beachfront rooms and tours cost resort prices, but market loncherías, taco stands, town-centre guesthouses and the cheap ferry make a careful budget workable.

On Ambergris Caye almost everything is shipped in, so food and drink cost North American prices or more. Days of diving and golf-cart hire add up quickly, and low season is the main way to cut costs.

Neither island has a theatre or concert programme. Evening music on both means a band or a guitarist in a bar. What differs is the local tradition. On Ambergris Caye you may hear Garifuna drumming and see punta dancing, and the summer lobster festival brings music into the streets. On Isla Mujeres folk dancing appears at local festivals.

Isla Mujeres is slightly more restful. Its slow routine of swimming, a hammock and sunset is easy to slip into, beach massages and yoga classes are common, and some places offer a temazcal, a traditional Maya sweat lodge. The streets near the ferry can be noisy in high season, so stay on the quieter southern or eastern shore.

On Ambergris Caye wellness comes mostly from the resorts. They have spas with open-air treatment rooms and yoga decks facing the reef, mostly well north of San Pedro and away from the golf-cart traffic.