Spotting scopes are a helpful tool in a large variety of situations.
1.) get a closer look at what you are hunting.
It is always interesting to see what you are shooting closer, especially to observe the details of a rare or great one.
2.) pick out rare waterfowl - if you are looking for a certain hybrid duck / want to individually pick out ducks, this will make it easier.
3.) get a better view of the overall landscape.
The scope would be anywhere from 15x- 30x+. You would set it up like the e caller. Would weigh 1kg.