LOL @ "it's all pipes" they're ALL connected!!!
Now, peeing while taking a shower is one thing, but yeah, peeing into the tub and not rinsing it out immediately afterwards can get a bit stinky.
You guys will think this is a bit gross, but when I cruised around Lake Ontario on my 30' sport cruiser, to save having to pump out often all my boat buddies and I would simply pee in the stainless sink. (this was before they made grey water tanks mandatory). We'd just rinse it out immediately afterwards when we washed our hands. Whenever we'd go to a boat show or ?? and check out new boats, we'd always check the height of the sink in the head. We even went so far to talk to some OEM reps about why they didn't put urinals in boats. It does save a LOT of pump outs. Imagine 6 or 7 people, all drinking beer for an afternoon, you can fill up a holding tank in no time. There was this one chick (friend of my GF's at the time) who would have 1 beer and I swear to go she'd pee out 2 gallons. One time we had a rafting party and she topped up the holding tank in 3 boats.......It got to the point where no one would let her drink beer on board....
I don't know what it is, maybe the fresh air blowing across the wiener, but nothing, absolutely NOTHING beats peeing outside......even in winter......My well got plugged 3 weeks ago and I was without water for 5 days and had to pee outside. It was a small benefit to an otherwise pain in the ass situation.......If I'm out gardening or working it's great to just step off into the bushes and let fly.......