Language: jargon: sailing
Mast Band: Naut.
n.- A strap, cable, or fitting around a mast under tension.
As commercial and military sail craft developed rigging techniques which allowed taller masts and larger sail areas, masts grew in diameter to compensate for the increased compression loads. The increased weight aloft, however reduced the effectiveness of tall masts by raising their center of gravity unacceptably high. To reduce the weight above the deck, bands were wrapped around the mast to allow them to be of smaller diameter without exploding under the compression loads.
Very quickly these mast bands developed in two different ways: they grew wider, covering a larger and larger percentage of the lower mast, and equipment was mounted to them, such as belaying pins or pad eyes for attaching gear. The former lead directly to the all iron masts of the late 1800s, and eventually to the aluminum extrusions and exotic fiber composite plastic masts of modern boats.