Section 708(iv) in Police Regulations, Bengal , 1943
(iv)The escort commander shall be particularly careful to see that each box designed for water conveyance, or having to cross any stream in transit by land, is attached to a buoy, formed of a piece of unsplit bamboo about 3 feet in length and not less, than 9 inches in circumference, with a rope at least 20 cubits in length, one end of which shall be fastened to the box and other to an orifice in the bamboo buoy. The length of rope shall, of course, be increased in proportion to the known depth of the rivers by which the treasure is to be conveyed. This rope shall never be wound about the box, but shall be loosely coiled with the buoy upon box, so that, in the event of the boats sinking, the buoy may readily indicate the position of treasure and lead to its immediate recovery.
