RL Question: How to dock a sub

[LoBlo]

RL, but somewhat random question. I'm curious how subs are tied to the pier of their dock. Is it just a matter of tieing one rope to the bow and one rope to the aft and making ithem snug? Does the sub bump up against the dock much and if so, does it damage the surface coating any? Also, how often is the sub treated for barnacles?

Also, do subs ever push off on their own (with maneuvering prop) or do they always have to use a tug? When the sub is in the channel away from the tugs and on its own power, is it at the Captain's discretion to maneuver as fast as he feels is safe, or are their restrictions to what speed he's allowed by Navy rules.

I've never actually seen a sub dock or leave port in RL so am curious to how its done. Thanks

lb