Please be sure to practice digging plugs before you go to public properties or permissions. Most (if not all) incorporated towns and cities have websites. These websites normally have a link to their ordinances which are the local laws and penalties. I also go to county parks sites to see their rules. The internet has made it so easy to find out this info. I mean not as easy as asking on a forum. I also recommend you go to the Maryland forum to pose this question as stated in the previous post. There should be other MDers in your area to get to know and maybe buddy up on occasion. Tnet is my home but I also belong to some local and state Detecting efff beee pages. There has to be some for your area and state. It is legal for me to hunt all public schools, town parks, and other public lands. In my county and most of the others around mine. The county parks require a permit per day and time period. The state parks here it is legal to detect the sandy part of the beaches without a permit, all other areas require a permit issued by the park manager which expire at the end of the year. All permits I mentioned for detecting are free.
Good Luck & Happy Hunting