On 21 September 1945, Motor Torpedo Boat PT-617 was completed at Electric Boat Co., Bayonne, NJ. The boat was assigned to MTB Squadron 42 and slated for service with the Pacific Fleet, but this was later cancelled.
On 16 September 1890, steam coaster SS Robin was launched at Mackenzie, MacAlpine & Co, then Robert Thomson, Orchard House Yard, Blackwall, London.
On 16 September 1943, Iris-class 180-foot buoy tender USCGC Bittersweet (WLB-389) was laid down at the Zenith Dredge Company, Duluth, Minnesota. She was transferred to Estonia on 5 September 1997 as 'Valvas' (PVL-109), and is now a museum ship in Tallinn, Estonia.
On September 4 1990, the Tench-class submarine USS Requin, arrives in Pittsburgh at the Carnegie Science Center.