Although tourist areas are generally safe, visitors should always stay alert, even in laid-back Hawaii (and especially in Waikiki). It's wise to ask the island tourist office if you're in doubt about which neighborhoods are safe. Avoid deserted areas, especially at night. Don't go into any city park at night unless there's an event that attracts crowds -- for example, the Waikiki Shell concerts in Kapiolani Park. Generally speaking, you can feel safe in areas where there are many people and open establishments.
Avoid carrying valuables with you on the street, and don't display expensive cameras or electronic equipment. Hold on to your pocketbook, and place your billfold in an inside pocket. In theaters, restaurants, and other public places, keep your possessions in sight.
Oahu has seen a series of purse-snatching incidents, in which thieves in slow-moving cars or on foot have snatched handbags from female pedestrians. The Honolulu police department advises women to carry purses on the shoulder away from the street or, better yet, to wear the strap across the chest instead of on one shoulder. Women with clutch bags should hold them close to their chest.
Remember also that hotels are open to the public and that in a large property, security may not be able to screen everyone entering. Always lock your room door -- don't assume that once inside your hotel you're automatically safe.
Recently, burglaries of tourists' rental cars in hotel parking structures and at beach parking lots have become more common. Park in well-lighted and well-traveled areas, if possible. Never leave any packages or valuables visible in the car. If someone attempts to rob you or steal your car, do not try to resist the thief or carjacker -- report the incident to the police department immediately. Ask your rental agency about personal safety, and get written directions or a map with the route to your destination clearly marked.
Generally, Hawaii has the same laws as the mainland United States. Nudity is illegal in Hawaii. There are no legal nude beaches (I don't care what you have read). If you are nude on a beach (or anywhere) in Hawaii, you can be arrested.
Smoking marijuana also is illegal. Yes, there are lots of "stories" claiming that marijuana is grown in Hawaii, but the drug is illegal; if you attempt to buy it or light up, you can be arrested.
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.