This is the Oliver + S sailboat top, size 6m, made in a cotton from Joann's. I really like the buttons at the shoulder and the hem detail.
I really like this top, but it is a little hard to get on wiggley babies. I have seen it on flickr in knit and think I will go that route next since it will be easier to get on:)
Modeled by my sweet little Georgia in her bumbo, before she could sit on her own:)