How many?

Inches

The inch is a unit of length in the British imperial and the United States customary systems of measurement. Since the adoption of the international yard during the 1950s and 1960s it has been based on the metric system and defined as exactly 25.4 mm. The standard size pencil that you may see in schools and offices is 7 inches long.

Fathoms

A fathom is a unit of length in the imperial and the U.S. customary systems equal to 72 inches (1,828.8000 mm), used especially for measuring the depth of water. The Atlantic Ocean at its deepest point is believed to be 4,580 fathoms deep.