As I was looking for my first bath-related design ideas (since it is my new work field), I have been lucky enough to find a great one on one of my favorite webblog, Designboom.
As explained by the blog, the transparent bath displays the number of drinkable water bottles you are using when taking a bath. It has been designed by Belgian Flore de Crombrugghe and is one of the results of Addictlab's Brussels based lab project with interior design students.
The bathtub is just a concept right now, but a sobering idea nonetheless.
I am not sure every bath addict would be really pleased to be reminded, each time they soak for a relaxing moment, how much drinkable water they are using. Though consumers most concerned with sustainable development will probably love the idea.
Yet there might be another positioning for it, for weight-loss-diet-addicts! : "Visualize precisely how much you fill your bath, and how much the level changes when you dip in .. The more volume you lose, the less the level will change !"
Could be less effective than your teenage years denim trousers, but maybe that's the next cover for the women magazines Spring editions : the bath-volume diet !