sentences:  Keel-related traditions from the times of wooden ships are said to bring luck to the ship during construction and to the captain and crew during her later life.They include placing a newly minted coin under the keel and constructing the ship over it, having the youngest apprentice place the coin, and when the ship is finished, presenting the owners with the oak block on which the keel is laid.The tradition of the placement of coins derives from the mast stepping custom of placing coins under the mast and is believed to date back to Ancient Greece or Ancient Rome and were intended to "pay the ferryman" to convey the souls of the dead across the River Styx should the ship sink.