Keep a sharp eye on the scene when Mike O'Shay escapes from the brig by tricking a fellow seaman, the key was already in the cell lock - he could have gotten out at any time he wanted!
The Coast Guard ship is seen in port in San Pedro, California, but is then sent on an iceberg patrol in the North Atlantic. The map coordinates are hundreds of miles east of Nova Scotia, Canada. However, the address on the telegram sent to Doris states she was in New London, Connecticuit.