Just FYI, some of HAL's religious chaplains contribute more than just a Sunday service. One of our longer HAL cruises encompassed the entire week of Hanukkah. Thay brought an orthodox Rabbi on board. I happened to meet him and his wife on a tour and they were fun and very sharp. Later in the cruise, the Rabbi held an open forum chat in the Lido one afternoon. It was open to anyone. He started off by saying that anyone of faith has questions, even doubts, and sometimes you are just not comfortable asking the spiritual leader of your home congregation. Or already have and gotten kind of a canned answer of what the organization believes. He then said that since it was highly unlikely that any of us would ever see him again, we should feel free to ask away. Now, I am Christian, but found his leadership of the discussion and his answer to be very thought provoking and helpful. Something I will never forget. He also shared some of his own doubts, some of what he considered to be answers to his questions, etc. Frankly, I think I got more from that discussion than from many a formal service.
Just my experience here.