The actual origin of "Down by the Bay" is uncertain as it shares the melody with other songs.
[1] It is an Ionian Cantada, a style of folk music that originated in the late 19th century.
"[2] It has gained popularity as a campfire song among the Scouting Movement in Britain.
The chorus from this was used by the folk band, Fiddler's Dram, in their song "Johnny John.
"[3] The song lyrics are usually as follows: Down by the bay, Where the watermelons grow, Back to my home, I dare not go, For if I do, My mother will say: Usually, the insertion lyrics follow some kind of variation of the question "Did/(Have) you ever see(n) a _____ _____ing a _____?