U.S. intelligence collection activities at sea are not constrained by the Convention.
This matter was fully reviewed at closed hearings before the SSCI and SASC in 2004. At the unclassified level we can comment that those Committees concluded, after receiving testimony from DoD, CIA, and DoS, that the Convention does not affect US intelligence collection activities. Those agencies confirmed that testimony in recent correspondence to the SFRC.
With regard to innocent passage, the United States already obligates itself to abide by articles 19 and 20 of the Convention, and we are already formally bound to the same obligations in the 1958 Territorial Sea Convention.