ABOVE BOARD

Today, above board means without deceit or trickery, and the term comes right out of the seafaring traditions. The board refers to the topmost plank in the siding, and that important slab of wood shows up in numerous seafaring terms, such as on board, overboard, inboard, by the board and others. Back in the days of the buccaneers, when a pirate ship approached another vessel at sea, most of the crew would hide below so that there appeared to be no threat. On the other hand, when the crew could be seen "above board", that signified they were not being deceitful about their intentions.