The Mediterranean is NOT non-tidal. And though I've seen the "Strait" of Gibraltar and the "Straits" of Gibraltar in print, I agree with you that it should be "Straits." The tides entering through the Straits of Gibralter decay rapidly in the Alboran Sea and generally the tides are rather small in both basins of the Mediterranean, the Eastern and Western. ---http://www.ssc.erc.msstate.edu/Tides2D/med_sea.html The Mediterranean Sea is virtually without tides because the tidal waters do not get far past the Straits of Gibraltar before falling back out into the Atlantic Ocean. Because the Mediterranean was the only sea the ancient Greeks ever sailed, the concept of "tides" was unknown in classical Greece. One intrepid Hellene, Pytheas (around 300 B. C.) sailed along old Phoenician routes past Gibraltar and as far as Britain and Scandinavia. But Asimov's Chronology of Science & Discovery said that few of Pytheas' compatriots believed his accounts of the strange lands to the north. The Greeks rejected his descriptions of the harsh waves that lashed the shores twice a day. They would not accept the rising and falling of water at predictable intervals. ---http://www.co.beaufort.sc.us/bftlib/tides.htm So the effect is that the water in the Mediterranean sloshes back and forth twice a day, like water in a shaken bowl. "The currents in the Gibraltar Strait are, generally, eastbound since the influence of the water contribution from the Atlantic to Mediterranean seas prevails (due to the high evaporation of this sea) over its own currents by the difference of tides." ---http://www.windtarifa.com/acneg/rules1.htm I think what the above quote is trying to say is that the current moving westward at Gibraltar (due to tidal motion of the Mediterranean Sea) is much weaker than the flow of water INTO the Mediterranean from the Atlantic. That doesn't make sense to me: it seems that when the Mediterranean is "sloshing" westward, the Atlantic would ALSO be sloshing westward at the same time. I don't see how the westward flow from the Mediterranean into the Atlantic would be cancelled out by a flow from the Atlantic into the Mediterranean at times like that. BTW: That last URL is a website from the Gibraltar Strait Swimming Association! They post some very interesting rules for people who want to try swimming across the Straits of Gibraltar! A description of a tugboat trip across the Straits in 1900 said this: "One writer says, "The passage from Gibraltar is pleasant." Perhaps he would say the same of the English Chan nel. Some of the passengers who crossed the Straits in the tug Hercules would not be of this mind. The tide was flowing in from the Atlantic at seven miles an hour; the powerful under-current from the Mediterranean was pushing out its mass of waters; there was a strong wind blowing against the tide, and the Straits were white with wave crests. The dirty old cattle-boat wheezed and groaned and belied its name "Hercules," for once or twice it nearly turned around in mid-channel. At this the captain, who was born in Boston, though he looked like an Arab and talked a dozen tongues, said, "She's blamed hard to steer, but we'll get her through this time "; and so we did, but we had been on board exactly five hours. There was no cabin, and no comfortable seat; and one of the ladies who gratefully accepted the captain's bunk, so that she might lie down, repented afterwards in haircloth and Persian powder. If any of my readers intend to go to Tangier, let them choose a big French steamer or a smooth day, unless they are good sailors and superior to trifling annoyances." ---http://www.oldandsold.com/articles04/spain28.shtml

For water to flow it is necessary to have a higher level for water to come from and a lower level for it to go to. On an incoming tide the mouth of a harbour will have a slightly higher water level than the inner end, and when the tide turns the inner end will have a slightly higher water level than the seaward end. The Straits of Gibraltar are relatively narrow and water cannot flow in quickly enough to affect the majority of the Mediterranean before the tide turns. Apparently there is a similar upper flow/lower flow situation at the Dardanelles between the Mediterranean Sea and the Black Sea. Some years ago the BBC put out a very interesting documentary which I think was called "In search of the legend of Gilgamesh" or something similar. In it, one of the Constantinople locals showed how they used the lower flow to propel their boats, by hanging a bag of stones from the bow like a sea anchor.

i assure you the med is tidal ... twice daily and 3 times on sundays