The celestron oceana 8x42 monocular is waterproof and fogproof which gives full protection in wet conditions making them perfect for marine use compass is aligned with the vertical range finding scale of the reticle besides indicating the direction to or from an object the azimuth angle can be measured through the analog compass as viewed with the reticle each graduation of the compass equals one degree of angle built in graduated reticle with a horizontal and vertical graduated line int