In ship design the tumblehome's the narrowing of a ship's hull with greater distance above the water-line. Expressed more technically, it's present when the beam at the uppermost deck's less than the maximum beam of the vessel. A small amount of tumblehome's normal in many designs in order to allow any small projections at deck level to clear wharves (Pursey p. 218). Origins Tumblehome was common on wooden warships for centuries. In the era of oared combat ships it was quite common, placing the… (More on Tumblehome)