General comment -
These things are awesome and have saved my butt more than once.
Had a "on the X" spot located for a duck hunt. Had scouted it in the daytime and thought getting in (up the creek, through the flooded willows, around the stumps, etc.) wouldn't be a problem.
WRONG- pitch black with dense fog and I got as lost as a (you fill in). Spot light only makes it worse. Got 100yds off the ramp and couldn't even get back.
Phone app to the rescue. I have used GPS Hunt.