thats all well and good till one day it is left too long and the shower water souers in the bilge....i like having a sump pump and collector box in the drain in order to isolate the shower drain water that way you don't have to have the smell everWe owned a 1986 30 Catalina for 12 years. The shower drained directly into the bilge. There was no separate pump for the shower drain. No through haul to open. The plus side was the bilge got cleaned and flushed every time we did.