Convert from Q to shackle

Unit Definition (Q)
The Q is a metric unit of distance equal to exactly 0.25 millimeter (9.8425 mils) used by typographers and page designers in Japan, in Germany, and in other countries in preference to the traditional point. One Q is equal to about 0.71 point, a little more or less depending on the exact definition of the point. This unit is also spelled kyu.

Unit Definition (shackle)
The shackle is a traditional unit of length used for measuring the lengths of nautical cables and chains, especially anchor chains. Anchor chains are formed by using shackles to join short lengths of chain. When the anchor is dropped and the chain runs out, a seaman counting the number of shackles can report the total length of chain deployed. The size of the unit therefore varied somewhat, depending on the length of the short chains used. In Britain, the unit became standardized in the 16th century at 12.5 fathoms (75 feet or 22.86 meters). In 1949, the Royal Navy adopted a length of 15 fathoms, which is 90 feet or 27.432 meters; this brought the British shackle in line with the U.S. unit, which is usually called the shot.