Firth of Clyde
The Firth of Clyde is the estuary of the River Clyde, on the west coast of Scotland. The Firth has some of the deepest coastal waters of the British Isles and is sheltered from the Atlantic Ocean by the Kintyre Peninsula. The Firth lies between West Dunbartonshire in the north, Argyll and Bute in the west, and Inverclyde, North Ayrshire and South Ayrshire in the east. Kilbrannan Sound is a large arm of the Firth, separating the Kintyre Peninsula from the Isle of Arran. The Kyles of Bute separates the Isle of Bute from the Cowal Peninsula. The Sound of Bute separates the islands of Bute and Arran.
The Highland Boundary Fault crosses the Firth. The Firth also played a vital military role during World War II.
The Firth is sometimes called the Clyde Waters or Clyde Sea. It is customarily considered to be part of the Irish Sea.
Geography
At the north of the Firth, Loch Long and the Gare Loch join the Firth; these lochs are separated by the Rosneath Peninsula. Off Greenock, an anchorage known as the Tail of the Bank narrows the estuary of the River Clyde to wide. The River Clyde estuary has an upper tidal limit located at the tidal weir next to Glasgow Green.The geographical distinction between the Firth and the River Clyde is vague. Some refer to Dumbarton as being "on the Firth of Clyde"; while at the same time, the residents of Port Glasgow and Greenock often refer to the part of the Firth that lies to the north of those areas as "the river".
The Firth encompasses many islands and peninsulas. Twelve ferry routes connect them to each other and the mainland. The majority of the ferry services are run by Caledonian MacBrayne and one by Western Ferries, and many of the routes are lifeline services for communities living in remote areas. The Firth has no fixed link transport infrastructure connections, linking the shores or islands. The lowest fixed crossing over the Clyde is the Erskine Bridge, opened on 2 July 1971.
The Irish Sea and the Firth of Clyde's southerly boundary, as defined by the Scottish Government, is between the southern tip of the Kintyre Peninsula and Corsewall Point on the Rhins of Galloway.
The Firth joins the strait between Scotland and Northern Ireland, called the North Channel, at the north of the Irish Sea. The deepest part of the channel is the Beaufort's Dyke, at.
Highland Boundary Fault
The Highland Boundary Fault enters the Firth off the east coast of Kintyre Peninsula in the south. The fault crosses the south eastern tip of the Cowal Peninsula at Toward Point, where it can be seen on the surface by the presence of Old Red Sandstone. The fault continues to Helensburgh in the north, then continues past the east coast of Scotland. The fault can be followed across Scotland for at least. The fault is of great age and its remains are broken by more recent geological movement of the earth's crust.Sea Lochs
Fourteen sea lochs join the Firth, the largest being Loch Fyne.Peninsulas
- Cowal Peninsula
The ferries across the Firth save time compared to traveling "round by road", via Loch Eck side, the Rest and Be Thankful and Loch Lomond side.The service between Dunoon and Gourock in Inverclyde is operated by Caledonian MacBrayne, the Public Service provider. This service carries only foot passengers and connects directly with the ScotRail service to Glasgow.Western Ferries is a Private Limited Company; it operates the service between Hunters Quay and McInroy's Point near to Gourock. This service carries all types of vehicular transport, as well as foot passengers.
- Kintyre Peninsula
- Rosneath Peninsula
Firth Islands
There are many islands in the Firth. The largest three all have thriving communities and regular ferry services connecting them to the mainland. They are:- Arran
- Bute
- Great Cumbrae
Holy Isle, a small island lying in Lamlash Bay, Isle of Arran. At the north of the Holy Isle, there is a religious resort.
Firth Lighthouses
The Northern Lighthouse Board is responsible for some of the navigation aids around Scotland's coast. Others are the responsibility of the local Competent Harbour Authority.There are lighthouses at:
There are navigation beacons at:
- The Gantocks Rocks and Navigation Beacon, off the coast at Dunoon, Cowal Peninsula.
- Horse Isle Beacon, Horse Isle, Ardrossan Built 1811.
Firth shoreline settlements
Nature and conservation
The Field Studies Council has a marine research station, based in Millport, on the island of Great Cumbrae.Common seals and grey seals abound in the Firth. Harbour porpoises are also common. While dolphins are much less common, some were spotted in the upper reaches of the Firth in the summer of 2005. Very uncommon are humpback whales, as are the minke whales. Even rarer are orcas.
Also, in 2005, the Firth had the second-highest number of basking shark sightings in Scotland. These huge sharks seem to particularly favour the warm, shallow waters surrounding Pladda, south of Arran.
However, although commercial fishing was at one time intensive in the Firth's many fishing towns, today the only catches of commercial interest remaining in the Clyde waters are prawns, lobsters, herring, mussels, and crayfish.
Conservation
On 5 September 2000, the Inner Clyde Estuary received a RAMSAR designation with ite number 1036; the area covered is.In September 2008, Scotland's first No Take Zone was introduced in Lamlash Bay, on the Isle of Arran. The result of a community effort, led by the Community of Arran Seabed Trust. The NTZ was introduced to protect delicate marine communities, such as Maerl. Maerl is a slow-growing coral-like calcareous red algae and is an important Scottish species. Maerl beds are locations of high biodiversity and are crucial nursery grounds for both young scallops and young fish. Studies show that both scallop dredging and organic waste from fish farms, significantly impact Maerl. Scallop dredging on a Maerl bed has been found to kill over 70% of the Maerl. Monitoring the dredged bed over the next four years found no discernible recovery, suggesting that Maerl beds would require many years free of disturbance in order to recover.
In 2014, at the south of the Firth between Kintyre Peninsula and the Rhins of Galloway, on the North Channel boundary. Designated a Marine Protected Area, the , the NatureScot Site Code is 10414, the EU Site Code is 555560461. The MPA covers a distinctive sill where fresher water of the Firth mixes with the cooler, more saline water of the North Channel. This is a rich environment for plankton, which provide food for fish, that are in turn eaten by higher marine predators and seabirds.
On 16 December 2015, an area to the south of Arran received a Marine Protected Area designation.
Water quality
The water quality of the Firth is monitored by the Scottish Environment Protection Agency. SEPA have had a monitoring buoy located off the coast of Dunoon since 2009, with data collected every 15 minutes.Shipping
The Firth of Clyde has some of the deepest sea channels in Northern Europe. It can accommodate the largest Capesize vessels afloat today. As a result, the Clyde has one of the UK's leading ports, at Clydeport, part of The Peel Group. The facility handles cargo from container ships at the Greenock Ocean Terminal.Supertankers visit the Firth to deliver crude oil to Finnart Oil Terminal in Loch Long, which is connected by pipeline to the Grangemouth Refinery on the Firth of Forth. Both owned by Petroineos, a joint venture between Ineos and Petrochina. A second pipeline brings back refined oil products to the Finart Oil Terminal for export mainly to Northern Ireland. The Finnart Oil Terminal is due to cease operation by June 2025.
Shipyards
On the upper Clyde, at Govan and Scotstoun both in Glasgow, two major shipyards are still in operation. They are owned by BAE Systems, whose major client is the Royal Navy.On the lower Clyde, only one shipyard still operates, Ferguson Marine, which is located next to Newark Castle, Port Glasgow. The Scottish Government now own the yard.
The Garvel Dry Dock in Greenock continues in operation for ship repair. The large Inchgreen Dry Dock in Greenock is in occasional use.
The remains of former sites of shipyards on the Clyde are being redeveloped into areas that contain residential housing, leisure facilities, and commercial buildings.
On the Firth itself, Ardmaleish Boatbuilding are based at Ardmaleish, near to Port Bannatyne on the Isle of Bute.
Cruise terminal
The Greenock Cruise Terminal, operated by Clydeport part of The Peel Group. A new twin berth terminal was opened on 25 August 2023.In March 2025 the Greenock Cruise Terminal was leased to Global Ports Holding Ltd with a fifty year contract.
Visiting liners
Historic liner visits
- ''Queen Elizabeth 2''
Shipwrecks