Are young children required to wear Swim Diapers? Swim diapers are required for children three years of age and younger. Swim diapers are available for purchase at the Water Park. Was this article helpful? Related articles Do you have towels available to rent at the Water Park? Are there any restrictions on Swimwear at the Water Park? Does my LEGOLAND ticket include entrance to the Water Park? What is the water temperature at the Water Park? Can I visit LEGOLAND today and then the Water Park on another day?