This Cary Grant-Tony Curtis naval comedy falls within the typical comedy format for each. It's periodically amusing, but with few belly laughers. The caper with the stolen pig is probably the funniest. If you generally like Cary or Tony comedies, check it out. Most Cary comedies rather late in his career are too tame for me. This one is an exception. Tony is up to his usual tricks, with and without women, and Cary, as the sub skipper, is presented with an endless variety of embarrassing or critical situations.
A group of women forced to live for some weeks on a submarine with very cramped quarters and no provision for the possibility of a handful of women passengers will naturally create some embarrassing situations, which is the main source of humor. The unplanned painting of the sub pink heightens the impression of a substantial feminine presence on this sub. The very flakey operational condition of the sub, with motors backfiring and barely functioning, provides part of the humor, as does Tony's imaginative methods of obtaining critical supplies and parts. Tony's inexperience with subs and shipboard operations in general, means he begins as an underdog, proving his worth with his facility for finagling supplies from warehouses, etc..
According to the Wikipedia site for this film, a number of incidents are based on actual events during WWII. For example, USS Bowfin managed to torpedo a bus instead of its target. The toilet paper requisition caper is also based on an actual happening. The heat from a burning sub scorched the topcoat paint off a neighboring sub, revealing its reddish undercoat, hence rather reminiscent of the problem that led to the pink sub. There was insufficient white or red undercoat paint available to do the entire hull. Thus, it was decided to combine their supplies of each to make a pink undercoat. Unfortunately, they didn't obtain the gray overcoat before they had to leave the warehouse area. Thus, they were forced to remain conspicuous during their long trip to Australia. Tokyo Rose did broadcast a comment about the red-coated sub, suggesting that the US Navy had gone nuts.
Also, I didn't get the significance of referring to their sub as a pig boat until reading a review. Apparently this was a common nickname , based on the smelly interior of many such ships, especially if the water stills weren't working at full capacity, hence not enough for showers, or if the sewage release outlet wasn't working properly.