The Sea Task Force was an element of the Coastal Security Service,
itself a part of the South Vietnamese Strategic Technical Directorate.
The STF conducted operations alongside covert elements of the US military
engaged in missions concerning OPLAN 34A.  OPLAN 34A was the secret
US mission to conduct harrassment operations inside North Vietnam.
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Missions ranged from supply of covert action teams, to commando raids,
to coastal bombardments.  The primary vehicle of these units was the
US supplied Patrol Torpedo Fast, a boat of Norweigan design often
referred to as the "Nasty" or "Nasty Boat."  The PTFs were outfitted
with a number of conventional weapons, but were also equipped with
weapons for shore bombardment such as 3.5" rockets and 57mm recoilless
rifles.