James Rassmann, a Green Beret advisor who was aboard Kerry's PCF-94, was knocked overboard when, according to witnesses and the documentation of the event, a mine or rocket exploded close to the boat. According to the documentation for the event, Kerry's arm was injured when he was thrown against a bulkhead during the explosion. PCF 94 returned to the scene and Kerry rescued Rassmann who was receiving sniper fire from the water. Kerry received the Bronze Star Medal with Combat "V" for "heroic achievement", for his actions during this incident; he also received his third Purple Heart.
What does the Combat V mean?
heroic achievement