telltale compass

Noun

 * 1)  A compass installed in the cabin so that the captain or other officer may check the course of a ship without going to the deck; often upturned and suspended from the ceiling.
 * 2) * To my great surprise, however, when I emerged from my state-room and caught a glimpse of the tell-tale compass hanging in gimbals in the skylight opening of the main cabin, I saw that the ship was heading to the eastward! — Harry Collingwood, "The Pirate Slaver", 1895
 * 3) * The captain was quick enough, racing back to the companion and down the stairs in two bounds, where, although the cabin was half full of water, he contrived to wrench away the "tell-tale" compass that swung over the saloon-table; and he was on the poop again with it in an instant. The instrument, however, was heavy, but he had hard work to carry it with both hands; and he managed to get to the side with it. — J.C. Hutcheson, "Teddy", 1887

Translations

 * Finnish: juorukompassi
 * Hebrew: ; מַצְפֵּן הַתָּא