For many centuries Mor Hafren - the Bristol Channel - has been thronged with shipping, great and small. By 1900, Cardiff was the major port (in terms of coal exports) in the world, sending cargoes to the four corners. Newport, Barry, Swansea, Milford and many other smaller ports along the coast of South Wales also exported coal or were home ports to the now dismally diminished deep sea fishing fleets.

Today with only one deep mine left in South Wales, the number of vessels plying their trade in the channel is only a fraction of what it was in the years between the wars. Ironically in this age of super tankers and bulk carriers, bringing crude oil to the refineries of Pembroke and iron ore to the steelworks of Port Talbot, the aggregate tonnage is still considerable.

The natural hazards to shipping remain, but motor power, echo sounding, radar and other aids to navigation have greatly diminished the numbers of casualties among commercial craft. Long gone though is the threat to shipping from the infamous German U-Boat which, especially during the first World War, wreaked havoc on the British Merchant Fleet using Welsh ports.