Leave Her, Johnny was a pumping song. Pumping songs would be used while pumping the ship dry. This particular one was sung at the end of a journey when a shipped would be docked.
This is also known as a growling shanty. Growling shanties communicate disapproval of the living conditions of a sailor. Since sailors would be punished if they were to complain to an officer of the ship, they would present their frustrations in the form of growling shanties.
Wareham Whalers:
http://www.wareham-whalers.org.uk/
Wareham Whalers Facebook:
https://www.facebook.com/warehamwhalers/
