Current and wind dictated this coarse of navigation. sailing against the trade winds was just about impossible with the craft of the day. Beating up wind in a galleon was darn near impossible. The coast of Mexico, and the Yucatan peninsula is very inhospitable, and many a ship perished in North winds and no secure anchorages. So up into the gulf where wind and current helped the journey. Sailing was tough back then and land was nessacary to keep in sight for navigational land marks. This was a normal practice in the time of galleons, and is a well documented route for some galleon traffic. If you missed havana and got west of it, then it may take weeks to beat back upwind to havana. Water and food could run short, and you may be cast ashore on a desolate shoreline!!