While I don't disagree, I have taken many showers using less than a gallon of water myself, Females with long hair don't always have that option (I swear I can fully shower with the amount of water it takes just to get her hair fully wet), and there are those times where a long hot shower just feels soo good, particularly after a long day of beating into crap weather.
I find it hard to imagine that anyone living aboard wouldn't be thrilled at the idea of this (the as yet unknown practicality aside for the moment)
I actually agree. For me, no, but if my teenage daughter was with me for long she would thank me.
Really, there are versions of this that would not be difficult to self build.
1. Ditch the first flush. Makes treatment simpler. Ofcourse, if you washed off in the ocean this is not needed.
2. Use hot water make-up from the heater during the recycle phase. This will cause some overflow, which is OK. Helps keep the water fresh. The recycle will be warm but not enough for some. Most on-demand heaters have a minimum flow of about 0.5 GPM.
3. Design the system to drain overboard after last shower. Avoids the nasty water problem, sterilization issues, and the need for carbon filters. The only filter would be to keep the shower head from clogging with hair.
This would yeild a 2-3 gallon shower, even with long hair, less for the rest of us or if semi-cool water was acceptable (it would be in summer).
The fact that most boats already have a shower sump pump helps. Some might chose to simply install a second shower head that runs off the sump pump; dead simple and easy for the user to understand which water is fresh and which is not.
It is automating it for public use that makes it complicated.
