deck gun
deck gun is a naval artillery or weapon type.
Overview
Naval artillery mounted on the deck of a submarine.
In detail
deck gun is a naval artillery or weapon type.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“Deck gun”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q1181970: deck gun
Consult the source