posted 11-20-2011 07:44 PM ET (US)        

--switch off transmitter immediately;

--switch equipment on and set to Channel 16; and

--make broadcast to "All Stations" giving the ship's name, call sign and DSC number, and cancel the false distress alert.

The USCG policy regarding inadvertent false distress transmission is in accordance with these guidelines:

-- Notwithstanding the above, ships may use any means available to them to inform the appropriate authorities that a false distress alert has been transmitted and should be cancelled.

--No action will normally be taken against any ship or mariner for reporting and cancelling a false distress alert. However, in view of the serious consequences of false alerts, and the strict ban on their transmission, Governments may prosecute in cases of repeated violations.

Source: http://www.navcen.uscg.gov/?pageName=falseAlerts

The above source also gives advice on how to cancel accidental satellite search and rescue beacon activations.