The government is afforded protection from liability in Suits in Admiralty Act (SIAA) actions involving permissible exercise of policy judgment, by the discretionary-function.

A claim arising out of allegedly negligent performance of a search of a vessel by the U.S. Customs Service and Coast Guard will be disallowed by applying the discretionary-function exception to the waiver of U.S. sovereign immunity found in the Suits in Admiralty Act.  The Customs Service derives its authority to board and search a vessel falls within the agency’s discretion.  The manner in which search has to be conducted also falls within the scope of discretionary-function exception.

Discretionary-function further includes the allocation of funds for construction of new aids to navigation requires policy judgments concerning the public interest too.  These matters should not be reviewed by the courts in the light of a tort claim under the SIAA.

In McMellon v. United States, 387 F.3d 329 (4th Cir. W. Va. 2004), while deciding an action to recover damages for injuries suffered by jet skiers when they went over the gates of a dam while riding jet skis, the court opined that “the wellspring of the discretionary function exception is the doctrine of separation of powers.  The principles of separation of powers mandate that the judiciary refrain from deciding questions consigned to the concurrent branches of the Government. The doctrine of separation of powers is a doctrine to which the courts must adhere, even in the absence of an explicit statutory command. To find the discretionary function exception not to be applicable to the Suits in Admiralty Act, courts would subject all administrative and legislative decisions concerning the public interest in maritime matters to independent judicial review in the not unlikely event that the implementation of those policy judgments were to cause private injuries.  Such an outcome is intolerable under the constitutional system of separation of powers.”