News

Notices

Shipping

Ships Expected

08/07/2008 - Minerva - Hatston 1

10/07/2008 - Costa Victoria - Anchorage Kirkwall Bay

Ships in Port

03/07/2008 - Crane Barge Missing Link - Hatston No 2

Ships Sailed

04/07/2008 - SKS Satilla - Flotta Terminal

04/07/2008 - Delphin - Hatston 1

Port Geography

Scapa Flow is a large marine basin located in the south of the Orkney archipelago. It has some 92 km of coastline and a surface are of about 156 km2 . It is formed by the surrounding islands of Hoy to the west, Mainland Orkney to the north and east, Burray to the east and South Ronaldsay and Flotta to the south. It is connected to the open water of the Pentland Firth to the south by the Sound of Hoxa, and smaller sounds between Hoy and Flotta and Flotta and South Walls, and to the Atlantic Ocean to the west by Hoy Sound. The original channels to the north and south of Burray were blocked in 1944 by the four causeways known as the Churchill Barriers. The coastline consists of Middle Old Red Sandstone, heavily contorted in places and broken with a small number of sand-filled bays. In the sub-littoral the sandstone quickly gives way to mixed sandy sediments which form the majority of the substratum of Scapa Flow.

The fetch over the basin is restricted to less than 20km in all but a small section of the northern shore which is exposed to the south across the Pentland Firth. This leads to a generally sheltered environment with moderately exposed sections in the north and east of the basin. However, severe winds cause a severe surface chop, reflected in more wave-exposed biotopes on the shore compared to the shallow sub-littoral.

The north shore of Scapa Flow from Houton to Scapa Bay consists of scalloped bays. Low-lying cliffs and boulder shores lead down into the sublittoral on the open coast with the bays comprising gradually-sloping sandy beaches and boulder platforms. The north shore is sheltered from wave action in the west becoming moderately exposed in the east. The east shore south to Howequoy Head consists of steep cliffs with broken slopes. It is linear in nature and moderately exposed to wave action. The south east of Scapa Flow is complex system of embayments formed by the causeways linking the islands. The embayments consist of gradual boulder slopes and bedrock platforms with wide sand beaches. The headlands and open sections of the coastline, south to Hoxa Head on South Ronaldsay, consist of small cliffs with boulder slopes leading steeply down into the sublittoral. The wave exposure of this area ranges from very sheltered in the embayments to moderately exposed at Hoxa Head. The island of Flotta to the south of Scapa Flow lies across the Sound of Hoxa from South Ronaldsay with low-lying cliffs and sloping boulder shores. The east coast of Flotta is moderately exposed to wave action, the north shore sheltered to very sheltered behind the Calf of Flotta.

Scapa Flow Suggested Tracks

The coastline of Scapa Flow generally shelves steeply to 20m, then more gently to over 30m in the majority of the Flow. The centre of the Flow is fairly level, punctuated by the steep-sided islets of the Barrel of Butter and Nevi Skerry. There are numerous embayments on the north and east sides of the Flow, which are less than 10m deep. The sublittoral rocks and boulder slopes of Scapa Flow give way to mixed sandy sediment which forms the majority of the substratum of the area. The circalittoral sediments are mixed with a greater percentage of fines than well-sorted sands of the infralittoral and sublittoral fringe. There is little input of silt into the system.

In the north west of Scapa Flow lie Hoy Sound and Bring Deeps, between Hoy and Mainland, extending around the island of Graemsay and southwards to Cava, leading into the main basin of Scapa Flow. The area is characterised by strong tides and water exchange in the west, around Burra and Clestrain Sounds, with decreasing tidal streams in the Bay of Ireland and through Bring Deeps.

Advertising

Advertise here

Advertise here

Advertise here

Advertise here