123Movies. Produced in 1945 by Jam Handy, "The Naval Gun At Iwo Jima" is a sister film to "The Naval Gun at Okinawa". This film details the important role Navy guns played in assaulting Japanese forces that were dug into caves on the island. It also shows the close support of Marines during the long assault. Naval gunfire at Iwo Jima was critical, the film explains, due to the fact that low visibility limited air operations. The film details the role played by battleships, cruisers, destroyers, destroyer escorts, and auxiliary gunboats. Shows tactics employed in exposing Japanese defenses, for example how gunboats were used to draw fire from Japanese gun batteries, exposing them so that the 16-inch guns on the battleships could used to destroy the shore positions.