Lyric discussion by jchvoid 

Cover art for Lethe Waters lyrics by Company Band, The

a dark night on a boat floating on the river maybe near an old mansion or a battlefield.

I should add that Lethe is one of the rivers in Hades. to drink from it causes complete forgetfulness. So maybe it's a ride on the boat of Charon headed to the afterlife. anything to fill in the picture.

According to traditional Greek myth and Dante's Divine Comedy, Charon only ferried cross Styx. "Lethe," more than just the river, is defined as oblivion or forgetfulness in the English dictionary - following Greek tradition that many bodies of water had literal meanings and was also named after a Naiad, which was more or less a personification of a body of water.