The Rosslyn was a 3679-ton Cardiff steamer built in 1902. She was 340 feet long with a beam of 60 feet. She was returning from Malta, in ballast, in February 1916 and was anchored out off the South Mole.
During the afternoon of the 28th a strong southwest gale caused her to drag anchor. Two government tugs went to her assistance, but with increasing winds could only manage to take off the crew. The ship foundered on the South Mole and sank the next morning, with the masts still protruding above the surface. These were dragged off so as not to be a hazard to navigation.
The wreck now sits at the bottom of the slope on a flat seabed in 23m, with the stern to the north.
The bow stands upright, 10m proud of the seabed, but with an increasing list to starboard. The starboard anchor, still on its chain, sits just beneath. Number one hatch is open, giving access to a large and well-lit cargo hold, from where it’s possible to pass through the small storerooms and chain lockers in the bow. Both winches and bollards may be seen on deck.
The foredeck is much more collapsed, with lots of covered spaces. Sections of mast are visible. The midships sits higher, and here can be found the two huge boilers sitting side by side with a small donkey boiler sitting on top. Hull plating covers the port boiler. Behind the boilers the steam engine sits upright and out in the open, easily the best example of this type of engine in Gibraltar. The aft deck is well canted over to the starboard side but the shaft is still in place in its tunnel, and the holds are fairly open.
The stern sits high but has an increasing list to starboard. It is possible to enter the stern compartments, and on top the rail, bollards, winches and the steering pinion for the rudder are visible. The rudder is still fixed to the stern and the cast iron propeller which shattered on sinking lies in sections beneath it. One of our favourite viewpoints is to swim below the rudder and look up at the curved stern end, towering over 12m above. It is an impressive sight.
A profusion of small fish, particularly Anthias and Chromis (damselfish) cover the wreck and occasionally lobsters are seen. In some of the cavities, especially between the boulders on the Mole slope, morays and congers can be found. Small but colourful life in the form of nudibranchs and gorgonians abound, and the latter especially carpet various surfaces white or purple/yellow.
Diving the Wreck
This is the largest wreck in Gibraltar and is easy to locate. It can be dived by most divers, hence its popularity. It is too big to cover in one dive, and some areas can appear to be fairly flat and plain, but there is a lot to see if you know where to look. The bow and stern sections are at present stable, with large, easily accessed open areas with plenty of light. The wreck however, has deteriorated over recent years. On a point of caution, be aware that occasionally strong currents run along the Mole. Also current flows around the wreck vary and can catch some divers unawares, particularly when emerging from the relative shelter of the wreck.
Extract courtesy of D. Fa. & P. Smith: Underwater Gibraltar - A Guide to the Rocks Submerged Sites.
SS Rosslyn upright bow.