Mazatlan or Zihuatanejo?

Both are first-rate beach towns, but the water behaves differently. Mazatlan has a long, almost unbroken run of open Pacific sand, from the rocky bays of Olas Altas to the hotel strip of the Zona Dorada and the wide, quieter shore at Cerritos, with Isla de la Piedra and Isla de Venados a boat ride away. The surf on the exposed stretches can be strong, and the sea is cool in late winter.

Zihuatanejo has the slight edge for swimming, because its sheltered bay keeps Playa La Ropa calm and the sea warm in every month. Las Gatas, behind its old stone reef, is flat and clear for snorkelling, and Ixtapa's long beaches add space, though El Palmar takes the full ocean swell.

Mazatlan eats better. As a shrimp port it has a deeper seafood repertoire: aguachile, smoked marlin tacos, pescado zarandeado at beach shacks, shrimp cocktails from morning carts, cheap breakfasts at the Pino Suárez market, and a local lager to go with it all. The restaurants around the Plazuela Machado give evenings a bit more choice.

Zihuatanejo's cooking is honest and fresh but narrower. Tiritas and pescado a la talla at the palapas of La Ropa and Las Gatas are the highlights, and Thursday pozole is a Guerrero custom worth joining. Beyond that, the market, taquerías and a few view restaurants are the whole of it.

Mazatlan has a genuine historic centre, built on 19th-century port wealth: painted houses, the arcaded Plazuela Machado, the Teatro Ángela Peralta and a twin-towered cathedral. The malecón adds cliff divers and the El Faro lighthouse on its hill. The museums are small, but there is a couple of days' wandering.

Zihuatanejo has almost none of this. The Museo Arqueológico de la Costa Grande gives a short introduction to the region's pre-Hispanic past, and the rest is the whitewashed grid, church and fishermen's pier of a working town, pleasant to stroll but over in an hour.

Mazatlan is the place for a night out. The Zona Dorada's open-fronted bars and dance clubs run late at weekends and fill with students in spring, while the old centre offers quieter drinks around the Plazuela Machado, all to a soundtrack of banda. Carnaval turns the malecón into a week-long party.

Zihuatanejo's evenings are sunset drinks, a long dinner and a few small bars with a local and long-stay crowd. For noise you have to go up the coast to Ixtapa, whose beach bars and handful of clubs only really fill in the winter high season and on Mexican long weekends.

These two are about level outdoors, and both live on the water: sailfish and marlin boats, humpback whales in winter, turtles on the beaches later in the year. The difference is in emphasis. Mazatlan offers point-break surfing near Olas Altas, island kayaking, the climb to El Faro and pine-clad Sierra Madre foothills within about two hours.

Zihuatanejo is better below the surface, with the snorkelling and diving at Las Gatas and Isla Ixtapa, and its calm bay suits paddleboards. On land its draw is wildlife: spoonbills at the Barra de Potosí lagoon and crocodiles in the mangroves near Playa Linda.

Mazatlan has the better excursions, because the Sierra Madre foothills are close. Concordia's baroque church and furniture workshops, the cobbled silver-mining village of Copala, El Rosario's gilded mission church and, at a stretch, Cosalá make a real change of scene from the coast.

From Zihuatanejo the options are mostly more beach: a surf day in Troncones, a fish lunch at Barra de Potosí. The Xihuacan ball court and Petatlán's pilgrimage church add a little history, but nothing larger is within easy reach.

Both welcome children in the easy Mexican way, and both lean on hotel pools and kids' clubs. Mazatlan has more to do off the sand, notably the large aquarium in the Parque Central for a hot afternoon, but its open beaches can be rough, so small children are better off in the island coves.

Zihuatanejo's advantage is the water itself: La Ropa and Las Gatas are calm enough for toddlers to paddle right on the bay, and the small town is easy to handle. Outings are nature-led, such as crocodile spotting, boat rides to Isla Ixtapa and turtle releases.

Getting about is similar in effort but different in shape. Mazatlan is a long ribbon: the 20km malecón links the old centre to the Zona Dorada, buses run the coast road, and the open-air pulmonía taxis make the trip fun.

Zihuatanejo is small and its centre walkable, but the beaches sit over steep hills without pavements, so it is taxis, colectivos to La Ropa and Ixtapa, and water taxis to Las Gatas.

Neither is a shopping destination, and both come down to crafts and beachwear. Mazatlan has the wider spread, with Zona Dorada silver and hammock shops, the Pino Suárez market hall, artists' studios in the old streets and ordinary malls. Zihuatanejo's artisans' market is smaller but has a stronger regional flavour, with Taxco silver and Olinalá lacquerware from the Guerrero mountains.

Both are easy on the wallet, with cheap market meals, seafood shacks, buses and taxis. In Mazatlan that comes from a mostly Mexican clientele, and rooms jump mainly at Carnaval, Easter and Christmas. Zihuatanejo's costs climb more in the winter high season and in the hillside boutique hotels above La Ropa, so a town guesthouse is the way to keep it cheap.

Mazatlan has a real stage in the restored Teatro Ángela Peralta, with concerts, opera and dance and an autumn festival built around it. Banda sinaloense, born in this state, is everywhere, from beach restaurants to strolling groups on the malecón.

Zihuatanejo has no theatre to speak of. Its musical moment is the annual international guitar festival, and otherwise it is trova singers, mariachis or a band in a restaurant during high season.

Zihuatanejo is the more restful of the two. The town moves slowly, there is nothing to rush to, and the boutique hotels above La Ropa and the Ixtapa resorts offer spas, with yoga and temazcal sweat lodges in some smaller places.

In Mazatlan rest is something you seek out. The Zona Dorada's music carries, treatments are mainly in resort hotels, and the quietest stays are at Cerritos or across the harbour on Isla de la Piedra.