This invention allows personnel located on two different structures, such as two ships, to continually monitor the separation distance between the two structures, with all of the necessary equipment being located on only one of the structures. This is accomplished using a laser range finder, or other range sensor, to continually measure separation distance and send it electronically to various displays. The displays are positioned and sized such that all involved personnel can view the continually updating separation distances. The invention incorporates displays large enough to be viewed ship-to-ship in direct sunlight, in addition to smaller displays. The displays are dimmable or backlit for night viewing and include a safety feature that turns them off when communication is lost with any range sensor. A strobe on the display helps personnel find where the display has been positioned, such as on a ships gunwale or hand railing.