Bobby Shaftoe's Gone To The Sea is an English nursery rhyme that is very old. It was first time published in 1805, so your kids' great-great-grandparents may also have used the this rhyme(!)
Bobby Shaftoe's Gone To The Sea probably has roots to the town Hollybrook in Ireland, where a person called Bobby Shaftoe lived in the early 18th century.
Let's sing this good, old rhyme!