With amazing water temp of 25-27c and tropical sun bronzing your body all you need to bring here is a aloha attitude, pair of lucky boardshorts and your good to go. Halewia the historic old town on the North shore hosts many surf shops including a Quiksilver Boardriders store.
On the northshore there are several places selling used surfboards. Unlike everything else here they tend to be cheap and if you are lucky will last the length of your stay (this depends on your luck).
Visiting Hawaii is a must for all surfers at least once in your life, the only thing you must prepare yourself for is crowds, my friend who lives here describes this factor as..'its never empty just less crowded than crowded..' nevermind, you really come here to watch the worlds best surfers pitting their skills against the power of the North Pacific ocean that bares down on the many reefs and beaches dotted along the Northshore. It is a great place to see different types of surfing equipment and ideas that you may be able to take home and try there.
There are more empty beaches than waves, which of course will keep your partner or family very happy indeed, my children have loved the beach and swimming in the bath like ocean. This is a big plus when choosing a family friendly destination. Hawaii embraces young famillies and nothing is too much trouble, a truly welcome host.
Pick the month you wish to visit to coincide with the water sport you are interested in.. Nov-Dec is the Triple crown of surfing Jan is the bodyboarding month and then finally comes Feb with the sup world tour contest at Sunset.
A word of advice, if you do live in or visit a special surfing destination that is quiet and offers good waves keep it to yourself or it may just end up as busy in the water as here.. then where will you surf and even more importantly your children after you?
Mahalo from the mecca of surfing :))