The eight mile wide Strait of Gibraltar separates Europe from Africa and connects the Mediterranean Sea with the Atlantic Ocean. Due to evaporation, the Med has a constant influx of water. Tides in the Atlantic and wind direction and strength will dictate the strength and direction of the surface and subsurface currents. With over four knots of current and 30 knots of wind at Tarifa 300 days a year these effects must be taken into account when transiting the Strait.
Our ride out the Med was smooth with 1-2 knots of favorable counter current hugging the coast staying just inside the easily visible current line. Rounding Tarifa the NE wind piped up from 5 to 25 kn and then died again as we approached Cape Trafalgar staying outside the shoals - all with 1-2 of favorable current. The wind got up to 25 kn again from the N as we approached Cadiz and the current went down to 1/2 kn. Some lumpy motoring into N chop for an hour or so.
We left at HW +5 (0830) and anchored just outside Puerto Sherry across the bay from Cadiz (20 ft, 36d34.78'N, 6d14.75'W) at 1700. There were three other yachts anchored here off a nice beach and there is a ferry to Cadiz docking in the Rio Guadalete at the town of Santa Maria nearby.