My 7 year old love's this. She is a bit taller for her age so we purchased a medium.  It's longer in the arms and length for her, but we will get some great use out of it through the year as she grows! It is a light weight/no liner rain/wind jacket. She can use it with a fleece or hoodie underneath on colder days and I imagine it will be perfect on the boat during the summer evenings!