myGMRS lists these 3,
Middletown DE - 462.55 Open, ~5 mile coverage southern New Castle county
Dover DE - 462.7 Open, ~10 mile coverage central Kent County
Tyaskin MD - 462.675 Open, ~10 mile coverage western Wicomico and southeast Dorchester counties
Any other repeaters usable in the region, hopefully open? Shout out to Towson, MD's repeater (462.6) which covers the Bay Bridge; and western Queen Anne's and Kent counties.