From this story on HometownAnnapolis.com:
_…The first operation began on Monday, as officers on routine patrol dragged grappling hooks through the water, looking for illegal nets, Windemuth said. The drift gill net season for rockfish had closed in mid-January, but was due to reopen yesterday. Officers sometimes find nets set out by watermen improperly or too early.
_…Using the grappling hooks, the officers discovered the nets at about 2 p.m. on Monday. Gill nets hang vertically in the water, so fish swimming by are trapped in the openings. In Maryland, only drift gill nets -- which aren't anchored and can drift in the water -- are allowed. They must be marked with floats on the surface and the watermen must be in the area. These nets under the surface weren't marked and there were no watermen around, Windemuth said.