You can't have 4 officers with you. Assign three officers in the "Passengers" screen. Their icons should appear next to yours at the bottom left of the screen. They should certainly follow you from ship to shore, they should follow you from one land location to the next, though they won't always appear inside buildings. (They do always follow me around, though I almost never use fast travel.) They should follow if you walk from Smugglers Lair to Leviathan Rock and they should follow if you fast travel and if "reload_tables.c" is set to teleport you to "reload", "locator3". But they might not follow if you change it to "goto", "locator11".
You can, of course, have a lot more than three officers on your ship. They'll contribute their skills and abilities without being in your party. Only those assigned to the squares in the "Passengers" screen will follow you around on land, though.
You can, of course, have a lot more than three officers on your ship. They'll contribute their skills and abilities without being in your party. Only those assigned to the squares in the "Passengers" screen will follow you around on land, though.