I have recently purchased what may be the most comfortable and useful shoes I've ever worn. Made by Crocs (whose other standard shoes I despise) these are bright red 'ballet pump' style, so really girlie - I even wear them to work (I am an architect though, and we're quite a laid back office) but at the same time very practical. They're grippy for avoiding slipping on the gunwhales, and made of some kind of rubber, so light and water resistant. They dry very quickly, but if you do get wet. they've got grippiness inside so your feet don't slide about. But most of all they're comfy - so squashy that I got an urge to bounce as soon as I tried them on!
Since I don't actually have a narrowboat yet, the only boat I've worn them on was a punt, but they fared admirably! Can't wait to wear them on Lucky Duck!
Oh yeah, and they cost £22.80, free delivery, with 5% promo code 46FF6, from KiddiKingdom