Joe Mann, U.S. Navy, USS Forrestal

Joe Mann, USS Forrestal, 1972-1976. Calibration of the carrier's PLAT / LENS System.
"I was enlisted on the USS Forrestal, mostly calibrating the landing
system for the incoming aircraft, known as the PLAT / Lens 
This is the same ship based department that facilitates the air wing. 
Other responsibilities were the arresting gear, and steam catapults.
You work your way through these to get to the PLAT (Pilot Landing
Aid Television) and LENS, The moving "meatball" that the pilots
use on final approach to hit the pitching flight deck at sea.
Here's a couple of shots of the PLAT equipment.  Photo 1, Photo 2
And a couple of shots of the LENS stansion: Photo 3
See also the Wikipedia article on the optical landing system.

All flight operations were taped, and If there was anything abnormal
about a landing, all the brass would come to our department for an
instant replay of the incident, and you better be able to
show it to them at any time... (without warning)

The adjustment of the LENS was a very critical part of the functioning
of air operations.  One mistake could cause the pilot to fly into
the back of the ship below the flight deck.  Needless to say the
pilots would always buy me a drink when we were at any port in the
Mediterranean sea. (the Med)  :-)

I was aboard the USS Forrestal from 1972 through 1976."