Guam or Saipan?

These two are very evenly matched for the beach, and both rely on a reef-sheltered lagoon on the west coast with warm, calm water for wading and snorkelling. On Guam the beach life is concentrated in one resort bay, Tumon, with pale coral sand, picnics at Ypao and better snorkelling under the cliffs at Gun Beach. Further afield there are rock pools at Inarajan and the Cocos Island lagoon in the south.

Saipan's lagoon runs the length of the west coast, but parts of it are seagrass and very shallow at low tide, so the finest sand is out on Managaha, a short boat ride away. Its east side adds small cliff-backed coves such as Ladder and Obyan Beach.

Guam is the better island to eat on. Its Chamorro cooking draws on Spanish and Filipino influences as well as island ones, and the night market at Chamorro Village and the roadside barbecue stands and local diners spread across the island give a curious eater plenty to explore beyond Tumon's ramen, Korean barbecue and buffets.

Saipan shares the red rice and kelaguen, adds Carolinian dishes and coconut crab in season, and has a decent run of Korean and Japanese places in Garapan. Away from the weekly street market, though, the choice narrows quickly, and a few days covers it.

Neither island holds a visitor for more than a day or two of sightseeing, but the history differs in kind. Guam's is spread across three eras: latte stones in Hagåtña, the Spanish plaza and cathedral nearby, Fort Soledad above Umatac bay, and the wartime landing beaches at Asan and Agat.

Saipan is almost entirely about the battle of 1944, and its memorials are harder-hitting: Banzai and Suicide Cliffs, the Last Japanese Command Post cut into the rock, and tanks rusting on the reef, with American Memorial Park in Garapan to explain them.

Evenings are low-key on both, and centre on one tourist strip. Tumon's Pale San Vitores Road is the bigger of the two, with sports bars and a couple of dance clubs that draw off-duty military as well as tourists, and it keeps going later at weekends. Garapan leans more towards karaoke and beach bars, and beyond its few blocks Saipan is quiet once dinner is over.

The outdoors is much alike in quality, and on both islands the best of it is underwater. Guam's divers head for the Blue Hole and for Apra Harbor, where wrecks from two world wars lie side by side. On land, the green south with Talofofo's waterfalls and Mount Lamlam makes for jungle walks, though the forests are oddly silent without their native birds.

Saipan's signature dive is the Grotto, a collapsed limestone cavern on the north-east coast. Its land is drier and rockier: the steep trail down to Forbidden Island, the lookout over Bird Island and the view from Mount Tapochau. The sheltered lagoon also suits kayaking and paddleboarding.

Saipan has the one proper day out between them. Tinian is a short hop by small plane, with the airfields of the atomic bomb missions and the giant latte stones of the House of Taga. Rota is also within reach for a night.

From Guam, the drive through Umatac, Merizo and Inarajan is the nearest thing to an excursion, and the neighbouring islands, Saipan included, are flights that suit an overnight stay rather than a day.

Both work well for a simple beach vacation with small children, built around calm lagoons and resort hotels with pools, slides and kids' clubs. Guam adds a little more: the Fish Eye underwater observatory at Piti lets children watch reef fish while staying dry, and in Tumon the beach, shops and restaurants all sit on one stretch.

Saipan's draw for children is the easy snorkelling straight off Managaha's sand and the quiet beach at Pau Pau. Its northern war sites suit older children more than small ones. Neither has a zoo or theme park for extra days.

On both islands you will want a car to go beyond the resort strip, as public transport is thin. Guam is the larger island, about 50km long, so the far south takes up to an hour, and Tamuning and Tumon have rush hours. In return, its shuttle buses link the hotels with Hagåtña. Saipan, at about 20km, puts everything within half an hour on quiet roads, and boats run out to Managaha.

Here the islands are far apart. Shopping is a main reason many Asian visitors pick Guam, with a large duty-free gallery and luxury boutiques along the Tumon hotel road and big American malls and an outlet centre in Tamuning and Dededo, all free of sales tax.

Saipan offers souvenir shops, convenience stores, a few resort boutiques and some crafts at the weekly market, and little else. Neither island has much in the way of independent shops.

Saipan is the easier island on the wallet, mostly because of its rooms. Its beach resorts are often more reasonable than on better-known tropical islands, and package deals from East Asia help.

On Guam, beachfront hotels in Tumon are priced like resorts in any developed country, and food runs above mainland American levels. Saipan's imported groceries are not cheap either, and on both a hire car adds to the bill, with the local barbecue stands and markets the thrifty way to eat.

Neither island is a place to plan around shows, and on both most visitors meet live performance at resort dinner shows of island dance. Guam has slightly more beyond that: a small symphony, university theatre and village fiestas through the year with music and dancing. Saipan's main occasion is its spring arts and crafts festival in Garapan, and otherwise it has no regular venue.

Both are simple places to rest, and neither has a spa or bathing tradition of its own. Guam has more resort spas and massage shops along its main road in Tumon, but the strip is busier. Saipan's foot-reflexology and massage shops in Garapan are matched by a quieter island around them, with early evenings and long lagoon days, which makes it slightly easier to switch off.