Wet 'n' Wild Hawaii waterpark is a great spot for family fun on Leeward Oahu. As many people would expect, Wet 'n' Wild is a great spot for older kids, but it also has many attractions for younger ones as well.
The "Keiki Cove" is a big hit with young kids. It features a large wading pool filled with small slides that young toddlers can use. It also has water spouts, and splashing, spraying water all over the wading pool. This area is a huge hit with kids of all ages (including babies!). Another popular area for young kids is "Water World", which has larger slides and deeper water for older kids (my 3-year-old enjoys playing in part of it, but he is still young for many of the slides and activities). Young kids also enjoy the "Kapolei Kooler" (a lazy river that you float around in inflatable tubes - parents can share their tube with kids too young to go on their own) and the wave pool. For a full list of the park's water attractions, click here.
Wet 'n' Wild Hawaii has other amenities that make it easier for parents of young kids, including: free life jacket rentals, shower and changing rooms, and locker rentals. Wet 'n' Wild does not allow people to bring in food from the outside (although they will make exceptions for food/drinks brought in for babies and toddlers). They have two dining areas that serve several kid-friendly items including Kraft Macaroni and Cheese and hamburgers.
For Oahu residents, getting a summer or annual pass is definitely the way to go. Regular adult admission for one day is $41.99 and regular child admission (ages 3 - 11) is $31.99 (there is also a $5 parking fee). The annual pass costs $99.99 for adults and children over 4 (it is currently on sale for $69.99). This annual pass includes free parking, unlimited admission to the waterpark, and unlimited admission to the neighboring "Island Adventure Golf" for 12 months. You can also choose to purchase the Summer Ultimate Fun Pass, which costs $41.99 and gives you unlimited admission until September 6, 2010 (you can pay $10 more and extend the summer pass to December 31, 2010). Click here to purchase tickets online (*tip: you will receive 10% if you purchase general admission tickets online).
Note: The waterpark tends to get very crowded in the summer months, especially on the weekends (During the week is not as bad, although occasionally preschools take field trips there making it more crowded than usual on weekdays). The winter months are far less crowded (we've had the Keiki Cove almost to ourselves in the winter), but the water also tends to be pretty cold during these months.
For more information: Please view my slideshow below for pictures of some of the attractions best for young kids.