There were going to be some incredibly stupid rules instituted in British Columbia but with the help of recreational boat lobbyists and magazines like Pacific Yachting, these moves were prevented. I must confess I can't take the dumping issue that seriously as Victoria dumps raw sewage into the salt chuck daily. What all recreational boater from the bottom of Puget Sound to the top Alaska dump out in ten years, if none of these boats had holding tanks, is less than what Victoria dumps out in one day. The population of Greater Victoria is around 330,000 and add to that all the tourist there in the summer and you have serious raw sewage waste going into the ocean on a daily basis.
I also read about Airhead and intend to use it. I sent an email to them - to be gross - on how well it handled very watery diarrhoea after a stomach had reacted to food; they wrote back that this issue wasn't a problem.
If I recall, the Airhead unit is suppose to handle a couple's "depositories" for 80 weekends before needing to be cleaned out. I think the urine bucked needed to be cleaned out every two days.
My old Catalina is still direct flow outlet from the head so at some point I know I will need to do something about it, but from an ex-RV'rs point of view, I'm not thrilled with holding tanks. I think the Airhead unit will fill the bill.