In 1906 the Harbour Master, Martin Boyd, devised a method of automatically indicating the height of the tide at the harbour mouth. The mast at the top had a series of balls operated by pulleys and floats at the edge of the water. The more balls that were visible the higher the tide. At night lamps were used behind shuttered windows up the height of the tower. As the shutters automatically raised with the tides, ships could determine how safe it was to enter the harbour. The remains of the float chamber can still be seen at the edge of the harbour adjacent to the tower.