The Condor Liberation struck the quayside at St Peter Port, Guernsey, while attempting to dock on 28 March. No-one was injured.
A report by Condor Ferries said the ship "landed heavily on a cylindrical single steel vertical piling".
The company said it would now work with harbour authorities to improve berth fendering.
The report stated: "The fendering on some of the berths in the Channel Islands, UK and French ports served by Condor is inappropriate for high speed craft."
Strong winds - with gusts of up to 32 knots - made it difficult to berth and the report noted "all pre-service port trials conducted in Guernsey and Jersey had only been conducted in moderate conditions".
The investigation also concluded using manual rather than auto settings on the ship "may have been more effective in completing the berthing manoeuvre".
However the report stated the master's use of auto "was reasonable given his previous experiences" and said the decision to attempt to berth "was reasonable".
The 102m (335ft) long vessel was built by Austal shipbuilders in Australia and can carry up to 880 passengers and 245 vehicles.
The Condor Liberation is the only fast ferry operating between Guernsey, Jersey and the UK.
Capt Fran Collins, executive director of operations at Condor Ferries, said the report showed the ship was "at all times operating within safe limits".
She said: "We will work with the ports to improve fendering and the continual assessment of the ship's manoeuvring system to identify and implement fine tuning to optimise manoeuvrability."
The crew of a £50m ferry has been cleared of being at fault for an accident in high winds.