The compass, which enabled mariners to know the direction in which they were sailing, has always been one of the most important navigational instruments. Introduced in Europe in the late 12th century, the compass was one of the earliest navigational instruments to be developed.

This is the earliest compass in the National Maritime Museum collection and dates from the second half of the 16th century. The case, lid and compass bowl are made of turned ivory. The compass is mounted in a brass gimbal ring, which reduces the effects of the ship's motion at sea. It has a soft iron needle, which is diamond-shaped and has a brass pivot cap in the centre allowing it to balance on a brass spike fixed to the bottom of the bowl. The needle is fixed to the underside of the vellum and paper card, which is divided into thirty-two points and hand-painted. The north and east points have additional decoration; this remained common until the 19th century, with east for Europeans being the direction of the Holy Land (and therefore often indicated by a cross). Most early compasses had wooden bowls; this example is made of expensive ivory, suggesting that the owner was probably wealthy.