The route from Cuba to Baltimore was one that passed by the Diamond Shoals. Special care had to be taken during the northward journey because the Gulf Stream propelled a ship along at a clip faster than normal. Ground speed could exceed a vessel’s cruising sped by several knots.
When a dense fog closed in on the Isle of Iona, obscuring the sun and the stars whose observation is mandatory in order to fix a ship’s position, Captain Quack’s only recourse for approximating his location was dead reckoning: a “guesstimate” calculated by multiplying engine revolutions by wind speed and direction and predicted drift. Thus, as darkness fell on December 13, the Isle of Iona was moving north faster than Captain Quack reckoned.
Instead of calling for a turn to starboard in order to round the dreaded shoals, he plowed straight ahead into the breakers on the south shore of Hatteras Island. All agree that the sea was rough, but according to different reports, the tide was either low or flood. The time was approximately 10:40 p.m. Coston flares informed those aboard the freighter that their plight was known to those on shore and within minutes both the Hatteras Inlet and the Durants life-saving stations were galvanized for action. By 10 a.m. the following day, all 27 men were brought to shore but the Isle of Iona eventually broke up where she lay.