To leave any port, you should plot a course...after all, isn't that the reason why you have a navigator on your crew? Plot the course on your navigational map, then your navigator takes over and makes certain that your sub gets out of the port. Plot the course to stay equal distance from the shorelines...(center of the waterways), to be safe. Get too near either shoreline and you run the risk of hitting subnets, mines or shoals/sandbars. As a last resort, you can adjust your speed to stay behind one of the escorts - usually a type 34 destroyer - and it'll safely take you in and out of ports. Also don't try to take shortcuts out of ports by using the narrow waterways between the main shore and islands. That's the best way of becoming a blockade ship, permanently anchored to the bottom of the sea.
