Surge – beware

Last couple of days at Queensway Quay Marina in Gibraltar has been “interesting”. We have a F7 easterly gale, meaning, in theory, Gibraltar should be a perfect shelter with a huge 400+ meter Rock just a couple of hundred meters to windward. After two sleepless nights we got a very physical demonstration to “surge”. We have 28mm polypropylene mooring lines that have served us well during the last 20 years (yes we change them every 4-5 years due to UV degradation and wear). After 48 hours the lines were almost broken due to the extreme surge. Surge is the phenomenon where water movements accelerates the boat to a dangerous level, it feels like you are crashing in to a harbour wall at 2 knots every 30 sec. Apparently very difficult to avoid when designing a harbor, I would guess it is the combination of very deep water (300+ meters just outside the breakwater), tides, right now 5 meters waves east of the Rock and katabatic wind gusts from the hill tops that creates this feeling of being in a washing machine. In August last year we considered this marina as our winter quarter. In hindsight, we made a very good choice in selecting Almerimar Marina as our base.