Two yrs ago I detected a sewer smell in my room and different locations on the ship. I wonder if this is still happening? It gave me a bad headache for the first 3 days, I guess I became immune to it afterwards.
When we sailed on the X Mercury...we noticed a strong sewage smell on our deck (deck 9) in the hallways. We didn't have to get use to it..the staff took care of the plumbing problem in one of the other cabins...after that...no bad odors.
In Sept/Oct we were on RCCI Monarch of the Seas...no problem at all... so I would complain if you smell sewage...let the staff know so that they will be a little more motivated to fix it. Most likely if you can smell it so can everyone else.
That particular offending odor is not part of the cruise experience!