Mary: By 1827 coastal routes would be well established and the use of the Gulf Stream current around Florida woul d have been common practise. Sailing vessels leaving New Orleans would directly This would take advantage of the Southeasterly flow from the Mississippi delta. The course set woul be towards Habana Cuba to a position off the Dry Tortugas 24* 00' North latitude and 83* 00' West Longitude. There is little seasonal variation in the currents; the strongest in the Florida strait are observed about 25* North to 80* West for about 300 miles North. Most wrecks are from Southbound vessels at night on the Florida reefs with the strong Northerly set. This usually involved overestimating the speed made good against a 3 to 4 knot current and the fact that the charts and surveys in those days were not very accurate. Coral reefs and reduced visibility were the hazards faced by early navigators. Northbound ships to Norfolk from New Orleans rarely ran aground unless they crossed the Gulf Stream to the western edge, and were set in to the Keys. For details you can visit the excellent museums in Norfolk. Yours,Aye Dave.
Ocean Passages For The World Royal Navy Hydrographic Dept.
British Marine Observers Handbook (ninth ed.)
Reference books easy to obtain at the library include- The Gulf Stream by William H. MacLeish
and anything about Lieutenant Matthew F. Maury
USA USNavy Oceanographic Office Pilot Charts.