In most cases it is lethal. They will sometimes drag whatever you are using for weight into shallow water though, and be waiting there for you.I'm pretty sure it is because all your beaver sets are supposed to be lethal. Whether foothold, snare or conibear. Footholds on a drowner would do the job, I don't see why a snare couldn't be used on a drowner either in a open water situation.
Would be nice if there was an exception but I'm sure that would get taken advantage of. First year trapping here so I'm sure others will have more info/corrections.
That reminds me of a story Belin told at a convention in Alma. I could never do it justice but it was about catching an otter out of season and having a rookie C.O. try to release it. It ended with a bang! Literally.I don't know why other than the chance of ricochet.
Trying to dispatch an otter without a gun or catchpole is a workout. A wet workout at that.