No single failure on the boat, short of sinking can be worse then when your head breaks. We got to experience this first hand.
Without delving into all of the sorted details (and making my mother in law feel bad) suffice it to say that we had our head completely stop working while we were down island with guests. As Dream Catcher has only one head, this constituted a major emergency.
I had rebuilt the pump once about a year or so before, but other than that I had a strict don't ask, don't tell policy with inner workings of my head. When it stopped working, I really had no idea where to start. Hind sight being what it is, I seperate out this next part to illustrate how important I now view this piece of advice:
BEFORE YOU LEAVE - MAKE SURE YOU KNOW HOW, WHY, AND WHERE YOUR HEAD WORKS AND HAVE THE PARTS ON HAND TO FIX IT.
Had I followed this simple plan, our head emergency would have been a two hour minor inconvienence. Unfortunately, I did not and as such I found myself on a boat with four people, two ferrets and no head for four days! All told, I had to chase parts around the Bahamas for 4 weeks before I got everything working correctly again.
We now carry not only a rebuild kit for our toilet, but also a completely new pump assembly. I also now know where the sewage pipe runs and how to get it out in one piece if it needs to be unclogged. We've also now started to pour a little Muratic acid down the head every few days with a teaspoon of cooking oil. The acid is to stop calcium buildups, while the oil helps lubricate the innards of the pump assembly.
Trust me on this one, take care of your head and be ready to repair it or you will live to regret it.