Hawaii is a place for taking part in sports rather than watching them, and active travellers will find the islands to be a paradise no matter what they are interested in doing.
Most famously, the surfing attracts people to the island of Oahu, with the legendary tube waves up to 100 feet tall crashing on the coast of the island around the famous North Shore. Less experienced surfers not wanting to risk life and limb may want to stay around the East end of Waikiki beach, where the waves are not so extreme.
Sport fishing is very popular amongst travellers to the islands, and there are plenty of opportunities to charter a boat and catch the big one if you take a trip off the coast.
Wind surfing is popular during the summer when the waves are smaller, and it is not uncommon to see boards scudding past if you go swimming in the sea during June.
Catering primarily to the US market means that Hawaii has many golf courses to choose from, and these can almost all be booked through the concierge desk of your hotel in order to get a discount. Happily many airlines flying to the USA allow you to take two pieces of luggage - i.e. a set of golf clubs and your suit case on the plane - although it pays to check in advance weather you might have any excess charges for taking golf clubs with you before you arrive at the airport.