They always used to say that while the army enjoyed "Wine, Women, and Song",
the poor old navy had to make do with "Rum. Bum, and Concertina".

I suppose that a concertina is a very compact melody instrument and is relatively robust especially kept in a wooden case, even compared to a fiddle. Sailors are often shown playing both fiddles and whistles, and in later times, I gather that harmonicas were also very popular.