This is the part of your vacation you've dreamed about -- the sun, the sand, and the surf. We'll tell you about the best beaches on Kauai, from where to soak up the rays to where to plunge beneath the waves for a fish-eye-view of the underwater world. Plus, we've scoured the island to find the best ocean activities on the Garden Isle. We'll tell you our favorites and give you a list of the best marine outfitters. Also there is a range of activities to do on dry land, from hiking and camping to the best golfing on the island.

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. We discuss all kinds of places to rent or buy gear.

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 (forbidden) 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.

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 Na Pali Coast on their own. But on Kauai, 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. I've recommended the best local outfitters and tour-guide operators.

But if you have the time, already own the gear, and love doing the research and planning, try exploring on your own. This guide discusses 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.

Local ecotourism opportunities are also discussed. For more information, contact the Hawaii Ecotourism Association (tel. 877/300-7058; www.hawaiiecotourism.org).

Booking via Activities Centers

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 Kauai.

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.