We spent 3 months in Gibraltar, we weren’t at all impressed with Queensway Quay Marina, the pontoons were neglected and the mooring cleats so rusty they chomped through ropes in a few days so we ended up using shackles on the ends of the lines! We were aware that there is a swell problem sometimes but weren’t expecting it to be so frequently and quite so bad especially with an easterly wind we had thought the marina would be protected by the land mass! The whole pontoon surged back and forth causing horrible jolts, we purchased rope snubbers which helped to dampen the jolts a little but It was still pretty awful at times, the only bonus being it was fairly sheltered from wind though and we were glad to be there rather than Marina Bay!