The canals of Deget are no place to swim. Not only are there boats freighting through, but those who fall in are summarily eaten by shark-like demons called rekhin. These creatures are sleek, sharp, and hungry.
The lute are a cousin of the rekhin that are more akin to jet streams than animals. They will tear their victims to pieces but this is only a side-effect of their races. Unlike the rekhin, lute do not eat people.