We start right away with the most important item, namely a life jacket! A life jacket ensures that your child, should they unexpectedly end up in the water, will stay afloat. Life jackets used to be very large in the past, but nowadays they are much smaller and children don't mind wearing them anymore! Whether it's good or bad weather, a life jacket should never be missing!
The clothing you dress your child(ren) in depends a lot on what you are exactly going to do and what the weather is like! In good weather, it is wise to wear swimwear or at least bring it along! Additionally, you can dress them in a UV shirt, which protects the upper body from sun rays. Unlike sunscreen, a UV shirt does not lose its protective function when wet, so the upper body is always well protected from sunburn! But if the weather is not so good, it is of course wise to dress your child(ren) warmer.
Children are often very active and they don't have to sit still on the water either! For example, they can hang behind the boat with a cool fun tube! But paddling a bit in an inflatable boat or kayak is a fun challenge for children as well. Do you feel like an active trip yourself? Then try paddling around on a sup board with your child!
If the weather is a bit changeable, dress your child in layers, so for example, a sweater can be taken off if it's very warm or a jacket can be put on if it gets a bit colder.