46 C.F.R. § 4.04-1
Link to an amendment published at 91 FR 39485, June 30, 2026.
A vessel owner, charterer, managing operator or agent shall immediately notify either of the following Coast Guard officers if there is reason to believe a vessel is lost or imperiled.
(b) The Coast Guard search and rescue authority nearest to where the vessel was last operating.
Reasons for belief that a vessel is in distress include, but are not limited to, lack of communication with or nonappearance of the vessel.