WHILE TAXIING THE FLOAT-EQUIPPED AIRPLANE TO DOCKING, THE PILOT SHUT OFF THE ENGINE IGNITION, AND IMMEDIATELY EXITED THE CABIN. HE THEN QUICKLY WALKED FORWARD ON ONE OF THE FLOATS IN ORDER TO KEEP THE AIRCRAFT FROM CONTACTING THE DOCK. AS HE WALKED PAST THE PROPELLER, WHICH WAS STILL TURNING, HE EXTENDED HIS HAND TO MAINTAIN BALANCE, AND THE PROPELLER IMPACTED HIS WRIST.