Md. Code, Natural Resources § 8–709.1

(a) This section applies to any public or private marina that is located on the navigable waters of the State.

(b) Except as provided under § 9–333 of the Environment Article, on or after July 1, 1989, a person may not construct:

(1) Any additional slips at an existing marina that would result in a total slip capacity of more than 10 slips; or

(2) A new marina with more than 10 slips on the navigable waters of the State.