Silver coin in question looks like a Spanish Realle.
W.O.T. ( wild orange thing) large coil for Explorers and Sov's that sort of looks like a basketball rim...many swear by it for large areas such as beaches and large fields for depth and coverage actually very light for its size approx. 15 inches...
Explorer depth would vary from area, but depending on area and coil and the ability to dig extremely deep probably 10-12 inches is more in the ball park for extreme depth but given the situation such as wet beach sand where digging is easy and coin is large such as a silver half or silver dollar can see where one could find coins in excess of a foot....but 18 inches would be really deep and not the norm...
W.O.T. ( wild orange thing) large coil for Explorers and Sov's that sort of looks like a basketball rim...many swear by it for large areas such as beaches and large fields for depth and coverage actually very light for its size approx. 15 inches...
Explorer depth would vary from area, but depending on area and coil and the ability to dig extremely deep probably 10-12 inches is more in the ball park for extreme depth but given the situation such as wet beach sand where digging is easy and coin is large such as a silver half or silver dollar can see where one could find coins in excess of a foot....but 18 inches would be really deep and not the norm...