It was on a spell during one of these start-up checks, after Sam had pointed to a perfect cloudform lagan building on one of the hedges, that Howard told him about the name. I thought it was named after the river in that old Irish song. You know, My Lagan Love. It's from the language of shipwreck. Flotsam, jetsam and lagan.
Flotsam is wreckage that floats when a ship goes down.
Jetsam is what's thrown overboard to lighten her. Jetsam when it's jettisoned, see. If it floats, it's flotsam. If it sinks, it's lagan. A lot of valuable stuff was marked with buoys so they could retrieve it later.