It's godd on fresh water beaches and shallow water up to the box. It also can notch out small iron which can help. Don't know about salt water beach if silencer and freq. adj. will help. Also I tie a small magnet inside my scoop to help with other small ferrous objects.
I wouldn't know for sure as I've never tested the 1280. I mainly use 1236x2 for competition hunts and around power transformers-which freq. shift and silencer works great. Maybe someone out there can clear this up for us?