We've gotta say it, the build quality of the Nav is right on par with that of high-end sunglasses, and the earcups adjust into position along the headrails with secure and satisfying clicks.
So the oil-services companies devised techniques (such as the Q-Fin system from WesternGeco and the Nautilus system from CGGVeritas) to measure and adjust the position of the streamers as they travel through the water.