Almost anywhere you go in Maryland, you will need permission before you can use your metal detector to hunt for hidden objects. State law forbids metal-detecting by individuals in state parks, except for public swimming beaches -- and even there you have to ask permission. Cities and counties usually require you to ask permission before searching on their property. And of course you should never metal-detect on private property without permission. Federal law forbids the digging up of relics in all national parks and other federal property. The only place you don't need permission is on your own property.
Ask permission from the property owner if you wish to metal-detect on private property. Talk to the owner in person if possible. Try to make a good impression by dressing neatly and treating the person with respect. The way you present yourself can make the difference between a yes or a no. Also promise that you will not damage any property or leave any holes in the ground, and it might help if you offer to let them keep anything you find.
Contact state park officials for permission if you wish to metal detect on state swimming beaches. The Maryland Department of Natural Resources allows metal-detecting on all state-owned swimming beaches except for Point Lookout and Calvert Cliffs. But you first have to get permission from the officials at the beach you wish to search. While you can then use a metal detector during normal park hours for most of the year, from May 30 through Labor Day, metal detecting is forbidden on the beaches between 9 a.m. and dusk. Park officials also have the discretion to suspend metal detecting at other times, such as during public events and festivals.
Contact the city or county parks department if you wish to metal-detect in city or county parks. Usually you can get permission from the local parks department. If you want access to other local government properties such as courthouse squares, talk to the city or county department responsible for maintaining the property.
Ask school principals or school superintendents for permission to metal-detect on school grounds or athletic fields.