I had was a center console fishing
boat, that came from the factory with a Porta potty. The porta potty was connected to a pump
out fitting though, but I do not think that was a requirement.
I know of no requirement to have a head on a boat, nor a holding tank
? People with desiccating heads I doubt have a tank.
The requirement I believe is to not discharge.
I had it explained to me by a FWC officer that it was illegal to pee in a cup and pour it off the side of a boat, but you could jump in and pee.
That is silly of course, but goes to the don't discharge point I believe?
By having a porta potty, I believe you are complying with the intent of the regulation
Course I've been wrong before