[tgusa]

gun decking = pencil whipping, i.e. filling out the paperwork without performing the actual task(s)

[Bryanw92]

http://www.urbandictionary.com/define.php?term=gundeck

This is what it meant when I was in the Navy.

[LonePalm]

The term gun decking goes back to the pre-WWII battleships.

One of the required tasks for the navigator was the taking of noon sights. This requires that the sun be brought down to the horizon using a sextant. This gives the ship's latitude.

The horizon is not visible from the gun deck. Therefore, if you just used the tables to get the sun's or a star's altitude rather than actually taking the sights, you have "gun decked" your sights.

Hope this helps.

"Ceterum censeo 0bama esse delendam."

Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)

[Rodamala]

gun decking = pencil whipping.

[paterfamilias]

Here are 2 useful links:

Navy Acronyms: http://en.wikipedia.org/wiki/List_of_U.S._Navy_acronyms#C

Navy Slang:
goatlocker.org/resources/nav/navyslang.pdf

[NRA1995]

gun decking = recording false data, as in maintenance checkoff lists or test data results.

[semaj]

“Ticket punching” as in “getting your ticket punched,” in order to move upward in the rank structure.

[ViLaLuz]

Gun decking. Completing documentation fraudulently. Barry’s eligibility was gun-decked. John Kerry’s Purple Heart awards requests were gun-decked.