The old dockside buildings and warehouses of Swansea have been developed into what is now the Swansea Maritime Quarter. At the south entrance to the National Waterfront Museum, is the old south dock which is full of privately owned boats and yachts and the pontoon to which are moored several ships from the Swansea Museum. This is the Helwick Lightship (Lightship No 91), built in Dartmouth in 1937 and originally for use in Humberside. In 1971 it was moved to the Helwick Sandbank on the south coast of the Gower Peninsular, some 10 miles from Mumbles Head and 1 mile south of Rhossili. A standard crew would have been a Master and 6 other crew, it has no engine to power or move from its fixed mooring at sea and had to call on the assistance of a tug whenever any moves were required. It had several diesel engines used to generate electricity for the light and for the compressor used to make air for the fog horn. The 8 lamps in the main light gave off 650,000 candle power for the half second flash every 9.5 seconds and could be seen for many miles in the Bristol Channel. It was replaced by a larger, more modern lightship in 1977 and was bought by the Maritime & Industrial Museum that year. Many of her old fittings are still in place and visitors marvel at the small, cramped conditions which the crew of 7 must have experienced when on active service in all weathers 365 days a year. In 1987 the Helwick and Scarweather lightships were replaced by modern navigational aids.  Behind the Helwick is the oil-burning tug boat Canning, built in 1954. On the western edge of the Maritime Quarter development is The Meridian Tower, Meridian Quay at 107m it is currently the tallest building in Wales.