Sunday, October 04, 2009

Gibraltar

The weather forecast showed 4 days of perfect weather to make our way to Gibraltar from the Balearic Islands so we pulled up anchor and set off. We had two lovely days sail and then the weather turned against us. The new forecast predicted high winds right on the nose so we decided to take shelter instead of tacking back and forth into high seas. Our chart showed a protected fishing harbour on the Spanish Mainland coast so we headed for Carboneras. Sailboats are not usually allowed in the fishing harbour but because of the weather, they allowed us to take refuge.

Carboneras looked very much deserted at this time of year. Since it was mid-September and bad weather, there were none of the thousands of tourists that would fill it’s streets and beaches during the summer. There was very little to do or see in this sleepy town so we spent the next 5 days hiding from the weather stocking up on supplies for Toboggan for our next two legs in the Atlantic (a total of 28 days at sea). Over the five days, a few other sailboats took refuge in the fishing harbour and we had to raft up two deep because there wasn’t enough room. When the weather forecast showed that things were clearing up, the port captain told us we all must leave which was fine since we were anxious to get on our way.

We headed out for Gibraltar again and after a couple hours, a huge storm front moved in (that was not forecasted) and we again decided not to risk it so we took shelter in a small bay with a couple other sailboats. Finally on our third attempt, the weather held for two days all the way to Gibraltar. It was very British with double decker buses and classic phone booths.

Sailing in the area of Gibraltar is interesting because it is at the juncture of the Atlantic ocean and the Mediterranean Sea both of which have their own weather system. The weather can change very quickly depending on which weather system is stronger and overpowers the other one. Add to that the fact that the land is mountainous on both sides of the straight (at Gibraltar and Morocco) so the winds accelerate as they squeeze though the mountains on either side. You can be sailing along nicely in a force 5 breeze(17-21 knots) and all of a sudden it is force 7 (25 - 30 knots). The rule here is to always be reefed down and expect the unexpected.

The other challenge in the Strait of Gibraltar is the current. One million cubic metres of water per second flow through the Strait of Gibraltar from the Atlantic to the Mediterranean. The current flow is always west to east because only 1/3 of the water that is lost to evaporation in the Eastern Med is replaced by rainfall so the shortfall is made up from the Atlantic. Since the gap between Europe and Africa at the Strait is only 8 miles wide, the water rushes through at 1 to 2 knots.

Then, there is the tidal flow to consider. The tidal flow varies between 1 ½ to 3 knots so when it is flowing in the opposite direction as the current, the net speed of the water flow is negligible. However, when the tidal flow is in the same direction as the current, the total speed of the flow can be up to 5 knots which is a huge problem for a boat like Toboggan to sail against it when our average speed is only 5 knots (we would sail over the water at 5 knots but make zero headway towards our target.)

Fog is also a challenge from June to September, when a warm wind blows from the warmer Mediterranean and hits the cooler water coming in off the Atlantic, thick Fog often forms. This is of particular concern since it is a busy shipping channel with over 80 ships a day passing through the strait not to mention the local ferry traffic between Algeciras and Tangiers or Ceuta.

Taking all these things into consideration, and timing our arrival as best we could, we arrived at Gibraltar and dropped anchor in a large, safe, sheltered bay at the base of “The Rock”. There are many sailboats here waiting for a good weather window to run the gauntlet of the Strait of Gibraltar out into the Atlantic and south to the Canary Islands. Here we too will sit…and wait.

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