Emotional balance
The Marinheiro's sway is the sway of the deck, not drunkenness. In the vibration of Iemanjá and Oxum (Oshun), he helps to calm emotion and find the way.
Hail the Marujada! He arrives at the end of the cleansing, with the sway of the deck, and works spiritual cleansing, emotional balance, and cutting of spiritual attacks (demanda).