What is 'Davy Jones' Locker'?

An ancient marine tradition in the Royal Navey, any that died at sea, were given their last military issue, to make the trip. 6 ft of canvas, and 3 lbs of coal. The canvas was stiched to make a sack, into which the coal and corps was stiched. Put upon a hatch cover, prayed over, then dispatched on their way to Davy Jones' Locker.