Bareksten Navy Strength Gin 700mlBareksten Navy Strength Gin Navy Strength Gin is gin that is bottled at 57 58%ABV. The origin of Navy strength gin evolved from the idea of "proof spirits", a term which originated in the 18th Century. At this time, British sailors were given rations of rum; to ensure that the rum had not been watered down, it was "proved" by dousing gunpowder in it, then tested to see if the gunpowder would ignite. If it did not, then the rum contained too much water