Maryland Code, Natural Resources § 4-718

(a) A person may not use a haul seine greater than 960 feet in length in the tributaries of the Potomac River, and not greater than 1800 feet in length in the St. Mary's County waters of the Wicomico River and its tributaries. Any person who possesses a seine greater than these lengths while actively engaging in seining in these waters is guilty of violating this subsection.

(b) A person may set a licensed haul seine and gill net at a distance greater than one third the distance across a river, creek, cove, or inlet in any of the tributary waters of Charles County only to catch carp and catfish, notwithstanding any other section of this subtitle. A person may not set the net to impede or obstruct navigation or block in any way the main channel of the river, creek, cove, or inlet. Any person who catches fish of a variety other than carp or catfish in any net shall return them immediately to the water unharmed. A person always shall attend a net for catching carp or catfish. Any person whose net is found more than one third the distance across the waters where it is set without a person in attendance is guilty of violating this subsection. The provisions of this subsection do not apply from March 1 through April 30 and September 1 through November 30 in each year.

(c) A person may not set a net of any description to catch fish in the Wicomico River proper above Woodland Point in Charles County.