If all you want is a fabulous beach and a perfectly mixed mai tai, then Hawaii has what you're looking for. But the islands' wealth of natural wonders is equally hard to resist; the year-round tropical climate and spectacular scenery tend to inspire almost everyone to get outside and explore.

If you don't have your own snorkel gear or other watersports equipment, or if you just don't feel like packing it, don't fret: Everything you'll need is available for rent in the islands.

Travel Tip -- When planning sunset activities, be aware that Hawaii, like other places close to the equator, has a very short (5- to 10-min.) twilight period after the sun sets. After that, it's dark. If you hike out to watch the sunset, be sure you can make it back quickly, or else take a flashlight.

Setting Out on Your Own vs. Using an Outfitter

There are two ways to go: Plan all the details before you leave and either rent gear or schlep your stuff 2,500 miles across the Pacific, or go with an outfitter or a guide and let someone else worry about the details.

Experienced outdoors enthusiasts may head to coastal campgrounds or even trek to the 13,796-foot-high summit of Mauna Loa on their own. But in Hawaii, it's often preferable to go with a local guide who is familiar with the conditions at both sea level and summit peaks, knows the land and its flora and fauna in detail, and has all the gear you'll need. It's also good to go with a guide if time is an issue or if you have specialized interests. If you really want to see native birds, for instance, an experienced guide will take you directly to the best areas for sightings. And many forests and valleys in the interior of the islands are either on private property or in wilderness preserves accessible only on guided tours. The downside? If you go with a guide, plan on spending at least $100 a day per person.

But if you have the time, already own the gear, and love doing the research and planning, try exploring on your own. We discuss the best spots to set out on your own, from the top offshore snorkel and dive spots to great daylong hikes, as well as the federal, state, and county agencies that can help you with hikes on public property; I also list references for spotting birds, plants, and sea life. I recommend that you always use the resources available to inquire about weather, trail, or surf conditions; water availability; and other conditions before you take off on your adventure.

For hikers, a great alternative to hiring a private guide is taking a guided hike offered by the Nature Conservancy of Hawaii, 923 Nu'uanu Ave., Honolulu, HI 96817; www.nature.org/ourinitiatives/regions (tel. 808/537-4508 on Oahu, tel. 808/572-7849 on Maui, tel. 808/553-5236 on Molokai, 808/246-0543 on Kauai, and 808/939-7171 on the Big Island); or the Hawaii Chapter of the Sierra Club, P.O. Box 2577, Honolulu, HI 96803 (www.sierraclubhawaii.com; tel. 808/538-6616 on Oahu). Both organizations offer guided hikes in preserves and special areas during the year, as well as day- to weeklong work trips to restore habitats and trails and to root out invasive plants. It might not sound like a dream vacation to everyone, but it's a chance to see the "real" Hawaii -- including wilderness areas that are ordinarily off-limits.

All Nature Conservancy hikes and work trips are free (donations are appreciated). However, you must reserve a spot for yourself, and a deposit is required for guided hikes to ensure that you'll show up; your deposit is refunded when you do. The hikes are generally offered once a month on Maui, Molokai, and Lanai, and twice a month on Oahu. For all islands, call the Oahu office for reservations. Check their website for a schedule of guided hikes and other programs.

The Sierra Club offers hikes on Oahu, Kauai, the Big Island and Maui. They are led by certified Sierra Club volunteers and are classified as easy, moderate, or strenuous. These are half- or all-day affairs. Donations of $1 for Sierra Club members and $5 for nonmembers (bring exact change) are recommended. You can find the latest edition of the club newsletter on their website.

For more information on local eco-tourism opportunities, contact the Hawaii Ecotourism Association (www.hawaiiecotourism.org; tel. 808/954-2910).

Outdoor Etiquette

Act locally, think globally, and carry out what you carry in. Find a trash container for all your litter (including cigarette butts; it's very bad form to throw them out of your car window or to use the beach as an ashtray). Observe kapu (taboo) and no-trespassing signs. Don't climb on ancient Hawaiian heiau (temple) walls or carry home rocks, all of which belong to the Hawaiian volcano goddess, Pele. Some say it's just a silly superstition, but each year the national and state park services get boxes of lava rocks in the mail that have been sent back to Hawaii by visitors who've experienced unusually bad luck.

Using Activities Desks to Book Your Island Fun

If you're unsure of which activity or which outfitter or guide is the right one for you and your family, you might want to consider booking through a discount activities center or activities desk. Not only will they save you money, but good activities centers should also be able to help you find, say, the snorkel cruise that's right for you, or the luau that's most suitable for both you and the kids.

Remember, however, that it's in the activities agent's best interest to sign you up with outfitters from which they earn the most commission. Some agents have no qualms about booking you into any activity if it means an extra buck for them. If an agent tries to push a particular outfitter or activity too hard, be skeptical. Conversely, they'll try to steer you away from outfitters who don't offer big commissions. For example, Trilogy, the company that offers Maui's most popular snorkel cruises to Lanai (and the only one with rights to land at Lanai's Hulopoe Beach), offers only minimum commissions to agents and does not allow agents to offer any discounts at all. As a result, most activities desks will automatically try to steer you away from Trilogy.

Another word of warning: Stay away from activities centers that offer discounts as fronts for timeshare sales presentations. Using a free or discounted snorkel cruise or luau tickets as bait, they'll suck you into a 90-minute presentation -- and try to get you to buy into a Hawaii timeshare in the process. Because their business is timeshares, not activities, they won't be as interested, or as knowledgeable, about which activities might be right for you. These shady deals seem to be particularly rampant on Maui.

There are a number of very reliable local activities centers on each of the neighbor islands. On Maui, your best bet is Tom Barefoot's Cashback Tours, 250 Alamaha St., Kahului (www.tombarefoot.com; tel. 800/779-6305 or 808/661-8889). You can reserve activities yourself and save the commission by booking via the Internet. Most outfitters offer 10% to 25% off their prices if you book online.

Don't Leave Home Without Your Gold Card -- Almost any activity you can think of, from submarine rides to Polynesian luau, can be purchased at a discount by using the Activities & Attractions Association of Hawaii Gold Card, 355 Hukilike St., No. 202, Kahului, HI 96732 (www.hawaiifun.org; tel. 800/398-9698 or 808/871-7947; fax 808/877-3104). The Gold Card, accepted by members on all islands, offers a discount of 10% to 25% off activities and meals for up to four people. It's good for a year from the purchase date and costs $30.

Your Gold Card can lower the regular $149 price of a helicopter ride to only $119, saving you $120 for a group of four. And there are hundreds of activities to choose from: dinner cruises, horseback riding, watersports, and more -- plus savings on rental cars, restaurants, and golf.

Contact Activities & Attractions to purchase your card. You then contact the outfitter, restaurant, rental-car agency, or other proprietor directly; supply your card number; and receive the discount.

The best Outdoor Adventures

*  Witness the Whales: From December to April, humpback whales cruise Hawaiian waters. You can see these gentle giants from almost any shore; simply scan the horizon for a spout. You can hear them, too, by ducking your head below the surface and listening for their otherworldly music. Boats on every island offer whale-watching cruises, but Maui is your best bet for seeing the massive marine mammals up close. Try Trilogy for a first-class catamaran ride, or, if you’re adventurous, climb into an outrigger canoe with Hawaiian Paddle Sports.

*  Visit Volcanoes: The entire island chain is made of volcanoes; don’t miss the opportunity to explore them. On Oahu, the whole family can hike to the top of ancient, world-famous Diamond Head Crater. At Hawaii Volcanoes National Park on the Big Island, where Kilauea has been erupting since 1983, acres of new black rock and billowing sulfurous steam give hints of Pele’s presence even when red-hot lava isn’t visible. On Maui, Haleakala National Park provides a bird’s-eye view into a long-dormant volcanic crater.

*  Get Misted by Waterfalls: Waterfalls thundering down into sparkling pools are some of Hawaii’s most beautiful natural wonders. If you’re on the Big Island, head to the spectacular 442-foot Akaka Falls, north of Hilo. On Maui, the Road to Hana offers numerous viewing opportunities; at the end of the drive, you’ll find Oheo Gulch, with some of the most dramatic and accessible waterfalls on the islands. Kauai is laced with waterfalls, especially along the North Shore and in the Wailua area, where you can drive right up to 151-foot Opaekaa Falls and 80-foot Wailua Falls. On Molokai, the 250-foot Moaula Falls can be visited only via a guided cultural hike through breathtaking Halawa Valley, but that, too, is a very special experience.

*  Peer into Waimea Canyon (Kauai): It may not share the vast dimensions of Arizona’s Grand Canyon, but Kauai’s colorful gorge—a mile wide, 3,600 feet deep, and 14 miles long—has a grandeur all its own, easily viewed from several overlooks just off Kokee Road. Hike to Waipoo Falls to experience its red parapets up close, or take one of the helicopter rides that swoop between its walls like the white-tailed tropicbird.

*  Explore the Napali Coast (Kauai): With the exception of the Kalalau Valley Overlook, the fluted ridges and deep, primeval valleys of the island’s northwest portion can’t be viewed by car. You must hike the 11-mile Kalalau Trail ,kayak, take a snorkel cruise, or book a helicopter ride to experience its wild, stunning beauty.

*  Four-Wheel It on Lanai (Lanai) Off-roading is a way of life on barely paved Lanai. Rugged trails lead to deserted beaches, abandoned villages, sacred sites, and valleys filled with wild game.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.