The Firth continues south from Inverkip to reach the south tip of the Cowal peninsula where Toward Lighthouse, built in 1811, sweeps out its protective beam to approaching shipping. Here the last semblance of a river is lost and the Clyde opens into a wide sea estuary with many islands and narrow channels to endanger passing ships. To the west of Toward lie the picturesque and treacherous Kyles of Bute which swing north west then south east round the tip of the island of Bute. Further to the west lies the long and deep expanse of Loch Fyne, which provides spectacular diving but few shipwrecks. The major area described in this chapter centres around the islands of Great and Little Cumbrae and the south tip of Bute. Here the wide expanse of the Firth becomes two narrow channels, each just over a mile wide, one to the east and one to the west of the barren rocky island of Little Cumbrae. In 1757 the first lighthouse to be built on the river was constructed on top of Little Cumbrae to guide ships safely through these hazardous waters. With the coming of steam the dangers were further reduced as vessels no longer had to rely on the vagaries of the wind and it became usual practice to engage the services of one of the riverÕs fleet of steam tugs to ensure safe navigation of these narrow channels. South of Little Cumbrae the Firth widens out to over 15 miles and becomes considerably deeper, especially off the east coast of Arran, here the nature of the shipwrecks change. The open expanse of the Firth provides little or no shelter from the prevailing southerly winds and many of the vessels lost lost within this part of the Clyde are due to stranding or foundering in stormy weather conditions. Diving in the area covered in this chapter is similar to that described in the previous chapter especially in the northern section. A number of fairly intact wrecks can be found north of Great Cumbrae, again often the result of collision, sitting upright on the muddy seabed at between thirty and forty metres seabed depth. The number of collisions significantly reduces the further south one moves, the predominant cause of loss becomes stranding in storms or fog. For the underwater explorer this also brings a change in the nature of the remains of the wrecks. As a general view, southwards from here, the accessible wrecks are in shallower water and substantially broken up, first by the activities of the many salvage firms operating on the river and second, by the action of the sea itself. There are a number of wrecks in deep water south of Little Cumbrae such as the Urd, HMS Topaze and HMS Dasher, these wrecks are now being visited and explored by teams of experienced technical divers.