i found what i belive is a coin but i cannot make out what kind.
its the same size as a 5p but it looks more silver, it was about 9 inches deep.
just hope its not an eroded 5p.
PS. If i find a 5pwith my garrett ace 150 it always says nickle, but this one said coin

sorry can only show one side of coin, my camera is playing up
thanks for your help.
Luke m.