in subsection (a), nothing in a contract described in that subsection may create liability of the United States to a contractor for any act or omission for which the contractor is exempt from liability under section 311(c)(4) of the Federal Water Pollution Control Act ( 33 U.S.C. 1321(c)(4) ). 422. United States commercial space-based radio frequency maritime domain awareness testing and evaluation program (a) Testing and evaluation program The Secretary of the department in which the Coast Guard is operating shall carry out a testing and evaluation program of United States commercial space-based radio frequency geolocation and maritime domain awareness products and services to support the mission objectives of maritime enforcement by the Coast Guard and other components of the Coast Guard. The objectives of this testing and evaluation program shall include— (1) developing an understanding of how United States commercial space-based radio frequency data products can meet current and future mission requirements