A manned deepwater port's person in charge of vessel operations must maintain radar surveillance of the safety zone or area to be avoided when:

(a) A tanker is proceeding to the safety zone after submitting the report required in § 150.325 in this part;

(b) A tanker or support vessel is underway in the safety zone or area to be avoided;

(c) A vessel other than a tanker or support vessel is about to enter or is underway in the safety zone or area to be avoided; or

(d) As described in the deepwater port security plan.