Near the end of the movie is a great shot of a Martin P3M-2 seaplane landing in the ocean. Markings on the side of the plane show a "6". Only 6 P3M-2s were ever built.
About 75 minutes into the film, Ruby Keeler performs a tap dance. A small part of the beginning of that dance was performed two years prior with James Cagney in "Footlight Parade". However, the two films had different choreographers.
This film's earliest documented telecast took place in Providence Sunday 9 June 1957 on WJAR (Channel 10); it first aired in Portland OR Tuesday 6 August 1957 on KPTV (Channel 12), in Boston Tuesday 17 September 1957 on WBZ (Channel 4), in Sacramento CA Wednesday 9 October 1957 on KCRA (Channel 3), in Tucson Thursday 10 October 1957 on KGUN (Channel 9), and in San Diego CA Saturday 2 November 1957 on KFMB (Channel 8).
A reduction gear, as applied to ship propulsion, is used to step down the spin rate (rpm) between an input shaft (e.g., connected to a turbine) and that of a propeller shaft. There are many ways to do this, but they all have to do with gear design, radii, and/or shaft angle between the interacting gears. 'Coxswain' reads a slip of paper (at about 1h 9m) that tests him on diagramming a double reduction geared turbine. The 'double' reduction simply means that there is another (interim) reduction gear between the input shaft and the propeller shaft.