There are now ferries which bring you from the main island to the kingdom islands and back for 5 platinum coins. The travel takes 5-10 minutes depending on where you want to go.

You see the ships on the map now (when pressing 'M'), you also see the name, direction and kingdom of the ship.
Another addition are the custom markers: click on one of the markers on the left side of the screen and move it on the map. Once you have dropped it you can change the text with '/setmarker text'. For deleting a marker select it, then press the delete key or move it outside the map. Custom markers are goog for remembering where altars, player houses or entries of dungeons are.