Hi. We are planning to take the overnight Jadrolinija ferry (Marko Polo) from Rijeka to Split. When you book online it gives you lots of cabin/Berth options, but no explanation about what each has. For example, you can book a cabin 2-berth inside-run water 2cb. Or cabin 4-berth outside-sh/wc 4A. We are two adults and a 5 year old, so we would like a private cabin to sleep. Any thoughts?