RedactedNarrative: Vessel 1 w@as anchored while the Occupants were watching the air show.  Vessel 2 was anchored in front of Vessel 1 at this time.  The anchor on Vessel 2 did not hold and Vessel 2 drifted backwards into Vessel 1's anchor line; the anchor line of Vessel 1 then became wrapped around Vessel 2's propeller.  Vessel 1's anchor line then snapped.  The Occupants aboard the two vessels used their persons to hold the two vessels off from each other; during this time, the Operator of Vessel 1 bruised his leg.  Vessel 2 was later towed into port by a commercial tow company.