Orange_Burst, I am not sure if this is pertinent to your issue, but we had a boat last year that had a smell like sewer gas. After the first night we reported it to BYIYC. They said if was the batteries off-gassing. They sent a crew out to Cooper to change out the battery bank. Solved the problem, and we were extremely happy with the service and response team. I had never heard of this issue, so thought I would mention it here for others.