I must repsond to your reply.
I don't know where you live but I do think that most people in the US know that waiter/waitress do not get paid much in hourly wage. And that they depend on tips for a living. This is definitely not a good thing but we must live with it. And our goverment lets this happen. Until this changes and they are paid a decent wage then we do need to tip.
When you get good service you should tip accordingly. Now I'm not going to tell you what is proper (everyone has own idea as to this). Also if you do not get good service the same goes, you tip what you consider proper. As for mandatory tips most resturants do impose a tip on parties of (usually) 8 or more. And personnaly there have been times when this amount is definitely more than we would have left due to bad service. I do think mandatory can be bad for service at times.
A good server would not go after a customer complaining about the tips left and I would have done the same as you did in that situation.
As for tipping on a ship unfortunately being mandatory has both it's good and bad. For my experience on ships I have seen very good service and feel that those that get the tips have earned them. I hope you do too.
Akumal Mexico Reviews
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor Feb 2012, MSC Poesia Dec 2012, MSC Poesia April 2013