Markings shall be maintained until:
(a) The sunken vessel or other obstruction is removed; or
(b) The right of the owner to abandon is legally established and exercised.
Notices of abandonment of sunken vessels or other obstructions will not be accepted by the Coast Guard. Any notice of intention to abandon should be addressed to the District Engineer, Corps of Engineers, U.S. Army, within whose district the sunken vessel or other obstruction is located.