As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TERRIFIC VIBRATION IN NOSE AREA AFTER GEAR RETRACTION. RETURNED TO SEA. *S/D* NOSE LANDING GEAR FORWARD DOORS WERE FOUND OPEN UPON ARRIVAL. ALL HINGE POINTS AND LINKS WERE CHECKED. NO DEFECT WAS FOUND. MANUALLY CLOSED AND LOCKED DOORS. NO FURTHER REPORTS.