Definitely shoot the field, set out some dekes and give em the feeder call, those ducks that would go to the river will go for the field. so, you will get the best of both. Sounds like a fantastic spot. Lets hear how you do.
"teal, teal, albino teal....wait, those are seagulls...take em.
wait till they line up and cross, 1 shell 2 birds