Actually, ships are required to have 100% life boat (or boat and raft) capacity on both sides of the ship. This was a direct result of the sinking of the Adrea Dorria back in the late 1950's.
The ship suffered a collision with an other vessel, and started to list badly to one side and could not launch the boats on that side of the ship.
Every ship in the vacinity came to its rescue and they were using all the life boats available to tender between the ships. Everybody who survived the collision got off the ship, otherwise without assistance it could have been another Titanic.