There is only one i dabbled in a few years ago, Ship Simulator 2008. If memory serves it was pretty fun plus there were mods available including some monster tankers and utility ships. It wasn't overly complicated tho to be able to call it a 'sim'. I think it was just up/down/left/right for controlling with some ships having a couple of further controls. There was a variety of ships available from jetskis to tug boats to freighters. It also had its fair share of bugs and the graphics were not that great even when it came out so may be worth checking some youtube videos to see if it's what you are looking for. There have also been some newer versions, Ship Sim Extremes and World Ship simulator but the 'World' one isn't the best. Sorry couldn't be much more help i was just going off memory rather than repeating things you probably already know.
Cheers and thanks for any input!
