In Spanish, the word galeoto means “a procurer, a pimp”. It’s an out-of-the-way word, not often heard or seen; alcahuete is the term more commonly used. But there is a play (early 1900’s) by J. de Echegaray entitled El Gran Galeoto, which uses the word in the sense of a pander, or go-between, bringing lovers together. RAE gives “pimp” (alcahuete) as the only meaning of galeoto, and offers as a source (without a citation) a character in a work by Dante Alighieri. The reference appears to be to Paolo and Francesca in the Inferno, where Francesca says at one point that a book of Arthurian romances was the galeotto (i.e. go-between) between her and Paolo.
I don’t quite see how this links up with “galoot”. Was Dante’s galeotto a sailor? (Edit) perhaps what’s meant is that the book “steered” Paolo and Francesca into each other’s arms?
In English, “galliot” appears to have been a sailing vessel, a kind of galley.