Years ago when I bought my boat used, it came with a marine head and
unused holding tank. I forget what brand the head was except that it
was the highest rated one by Practical Sailor. I hated it. No matter
what I did, replacing all hoses, rinsing it, etc, it stank and so did
the boat. I spent more time working on it than all other boat systems
put together. One day in a fit of "I'm gonna simplify my life", I took
it out, wired the thru-hulls shut and replaced it with a porta-potti.
Then I carried that damned thing around in my truck for awhile till a
sailing buddy saw it and asked about it and I gave it to him. I then
gave the holding tank to someone else. Now, both of these people still
act as if I had done them some huge favor when all I wanted to do was
get rid of it. So, for getting rid of the smell of **** and gaining
some storage space, they think I am a great friend, best investment I
ever made.
After 2 porta-pottis, I am still very happy I did this and my boating
life is much easier and less smelly.