There was a vast number of campaign missions, always random in location as well as types of ships involved: a truly dynamic campaign. Sub sim skippers are never satisfied with "canned" missions and this contributed to the success RSR enjoyed. Some missions include only submarines, others include only a surface convoy, others include a surface task force (with carriers), and others come with both ships and subs. Helicopters with sonar dipping equipment and sonar buoys add a lot. With the most challenging settings, events get so complex, and occur so quickly, that having two people at the keyboard is a great help, and for beginners, almost a necessity (plus more fun). Trying to identify ships with signature analysis, running from incoming torpedoes, launching noise makers and decoys, dealing with several of your own wire-guided fish, and launching Harpoon and Tomahawk missiles makes for a very busy captain. Overall, a great submarine simulator that's still being played today. Highly recommended!