454: h later at which point it is known as ‘The Boars of Duncansby’. During the time of the SE stream there is additional turbulence off Duncansby Head, particularly to the East. The race temporarily ceases at the turn of the tide before forming in an ENE direction in the NW-going tidal stream (ebb) before ceasing again at the next turn of the tide. The race is particularly violent and dangerous when the tidal stream is opposed by gales in the opposite direction. During the east-going stream a race forms off Ness of Huna. This race can be particularly violent in an easterly or southeasterly gale.
530:
54:
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fairly distinctive due to their size, fin and markings. The male has a very tall, triangular and erect dorsal fin which is sometimes tilted forwards. Juveniles and adult females both have a smaller, sickle-shaped dorsal fin. When surfacing the grey saddle shows up over the black back, behind the dorsal fin. It has a conical-shaped black head, with a distinctive white oval patch above and behind the eye, an indistinct beak, white throat and large paddle-shaped flippers.
31:
401:‘The Merry Men of Mey’. Forms off St John's point in the west-going stream and extends as the tide increases NNW across the firth to Tor Ness. The worst part is over a sand wave field about 5.5 kilometres (3.4 mi) west of Stroma. The waves formed by this race form a natural breakwater with relatively calm water to the east of it, particularly noticeable when a westerly swell is running. Tides in this area can exceed 19 km/h (10 kn).
1266:
61:
393:
595:. Rare but being seen more often around May to August. A fish rather than a marine mammal, it spends most of its time cruising on the surface filter feeding. The dorsal fin can be seen moving steadily through the water with the tip of the tail moving from side to side behind it. Usually seen feeding inshore at high tide around here in the
557:, which is more common in this area having one of the largest British populations, also comes in a number of colours and live in colonies giving birth to white pups from October through to January. These pups do not swim at first until they shed their white coat. When giving birth seals can often be seen inland.
574:
are not very common but seen from time to time. Many different types visit the firth and may be seen anywhere at any time. Larger than porpoises, 2–3 m depending on the type, black, with the rear edge of the fin curved back at the top unlike the straight edge of the porpoise. Head has a distinct
563:
can be seen all year round in all parts of the firth although they tend to favour shallower water. They grow to about 1.5 m and are black with a broad based triangular fin which can be seen as they surface. They have a small, rotund body with a short, blunt head, no beak, and a small, triangular
485:
claimed that the
Pentland Firth could be "the Saudi Arabia of tidal power" with an output of "20 gigawatts and more than that". In July 2013 Thomas Adcock of Oxford University stated that the Firth "is almost certainly the best site for tidal stream power in the world" although a peer-reviewed study
581:
are mostly seen around May to July although may be sighted at any time of the year. Usually swim in a pod of a maximum of from six to twelve individuals led by a matriarchal female. Males can grow up to 9 m long and can be about 25% larger than females and juveniles in the pod. They tend to be
461:
In addition to ‘The
Swelkie’, races form at both the north and south ends of Stroma and Swona. Between the races there is a calm eddy which extends down tide as the tide strengthens. The races are highly visible with overfalls and whirlpools. Large swell waves can also be present, especially in bad
588:
are quite often seen in June and occasionally through to
October but also at other times of the year. Tend to feed in the up-welling water of the tidal races but can be seen elsewhere. Usually seen singly but may be in pairs. Grows to 7–8.5 m, black with diagonal white band on flipper and a
613:
is the most frequently recorded species in UK waters and probably the only one in this area. Grows to about 2.9 m with an elongated black shell spotted with white, which tapers to a blunt spike. Migrates to UK waters from the tropics in the summer to feed on jellyfish. There are four other
462:
weather conditions. When entering or leaving the eddies, crossing the races, even large powerful vessels can be pushed off course, such is the demarcation between the relatively calm eddy and the fast-moving tide in the races. There are other races in the firth particularly off Brough Head.
517:
project for 25 years. Consent was granted in
September 2013 for MeyGen to build a 9 MW demonstration project of six AR1000 turbines commissioning in 2015 with 86 MW planned for phase 1 by 2020. The second phase would install up to 400 turbines generating 398 MW.
363:
Consideration was also given to construction of a tunnel linking the islands to the mainland. The 10-mile (16 km) tunnel was initially projected to have cost £100 million based on preliminary studies carried out in 2005 but as of 2012 no further progress has been made.
376:
The Firth is well known for the strength of its tidal currents, which are among the fastest in the world, a speed of 30 kilometres per hour (16 kn) being reported close west of
Pentland Skerries. The force of the tides gives rise to overfalls and
589:
slender, pointed triangular head. Relatively small dorsal fin curved back at top at rear part of body. Will probably see the long back with small fin to rear breaking the surface although they are known to bow and stern ride the waves of vessels.
540:
can be seen at all times of the year in all parts of the firth. They usually bask on the rocks on the ebb (falling) tide since it saves them having to move as the water rises. Large groups of seals can be seen at the north of
439:
The ‘Duncansby Race’ forms off Ness of
Duncansby at the start of the SE-going tidal stream (flood). Initially extending ENE but wheeling gradually anti-clockwise until it extends about 1.5 kilometres (0.93 mi) NW some
404:‘The Swelkie’. The race at the north end of Stroma, off Swelkie Point is known as "The Swelkie". It extends from the point in an easterly or westerly direction depending on the tide and can be particularly violent. The
603:, area though may be seen in deeper water. Generally around 8 m long, greyish brown to bluish black with pale belly. Seen in northern waters in the summer, southern in winter. Often in groups of three or four.
381:
which can occur at different stages of the tide. Combined with gale-force winds, they often give rise to extremely violent sea conditions, which have caused accidents such as the 2015 sinking of the cargo ship
367:
The first recorded swim across the
Pentland Firth was by Coleen Blair in 2011. It has since been swum by others including Andrea Gellan (2011; fastest swim) Mark Cameron (2018) and Alison Lievesley (2020)
1003:
575:
beak. Often swim alongside the bow of vessels and frolic in the bow waves. Probably more than one usually swimming together in a more synchronised manner, sometimes leaping out of the water.
457:
The ‘Liddel Eddy’ forms between South
Ronaldsay and Muckle Skerry in the East-going stream (flood). A race also forms for part of the time off Old Head at the SE part of South Ronaldsay.
545:, from the lighthouse round to the north-west part of the island and at the south end in the area of the beacon and to the east between the old jetty and the lighthouse. On
195:
tribe who inhabited Orkney. Such was their marine prowess that there are also instances of this name referring to the sea lanes of the entire west coast of
Scotland down to
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1149:
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come in various colours with spots and have their pups in May, June and July. They are of a similar colour to the adults and can swim from birth, The
521:
MeyGen completed the longest-ever run of continuous tidal electricity generation in 2019 with 25 GWh produced, enough to power nearly 4,000 homes.
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species less frequently encountered in UK waters where they usually occur as stray juveniles carried by currents from warmer seas.
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turning the millstone Grótti, which grinds out the ocean's salt. The witches 'Grotti Finnie' and 'Grotti Minnie' feature in later
1070:
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Currents of up to 5 metres per second (11 mph) make the
Pentland Firth potentially one of the best sites in the world for
1279:
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states that "the Britons originally filled the whole island with their peoples from the English Channel to the Sea of Orcs".
53:
922:
van Rijn, Leo C. 2011. Principles of fluid flow and surface waves in rivers, estuaries, seas and oceans. Aqua Publications.
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360:. This is a small passenger ferry which ran in the summer months only until recently. It did not run in the 2024 season.
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In October 2008 tidal power developer Atlantis Resources Corporation (ARC) announced it was considering a site near the
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dorsal fin. They are usually seen singly or in small numbers although in the autumn many groups may be seen in
651:. Translated by Jón A. Hjaltalin & Gilbert Goudie. Edinburgh. James Thin and Mercat Press (1990 reprint).
478:
Energy Review of July 2006 claimed that the Firth could produce "10 to 20 GW of synchronous electricity" and
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Historically the Gills Bay area has been the main setting off point from the mainland to the islands of
479:
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Prior to the Norse occupation of Orkney the strait was known as the "Sea of Orcs" – a reference to the
677:
141:
609:. Very rarely seen, however, they are occasionally found caught in fishing nets in this area. The
1021:
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for a computer data centre that would be powered by a tidal scheme in the Firth. In October 2010
475:
259:
The most northerly point of the headland of Dunnet Head, Easter Head, is also that of mainland
568:. When in groups, they tend to swim in a more random fashion than dolphins who swim together.
346:
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180:"Petlandsfjörð", meaning "the fjord of Pictland", and is completely unrelated to the
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1106:"Tidal power from Pentland firth 'could provide half of Scotland's electricity' "
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Strait between the Orkney Islands and Caithness in the north of Scotland
1022:"Scottish Energy Review: Scotland's opportunity – Scotland's challenge"
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995:"Wave goodbye to hope of tidal energy exports, Scots politicians told"
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is the oldest continuous ferry service across the firth by the ferry
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The available power from tidal stream turbines in the Pentland Firth
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At the eastern end John o' Groats Ferries sail to Burwick, also on
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in the east, while on the Orkney (northern) side from Tor Ness on
571:
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he led suggested that the maximum potential of the Firth was 1.9
196:
35:
Looking across the waters of the Pentland Firth to the island of
1265:
1234:. First published in Edinburgh; The Royal Celtic Society, 1926.
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1195:"EGEB: Tidal energy hit a major milestone in Scotland in 2019"
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they can be seen around the midpoint of the west coast. The
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of tidal power, with one GW being a more realistic figure.
232:
In the middle of the Firth are two significant islands,
213:
On the Caithness (southern) side the Firth extends from
314:, started in 1856 as a continuation of the railhead at
1150:"MeyGen secures consent for 86MW tidal energy project"
902:
The International Institute of Marine Surveying (IIMS)
898:"Poor decision making led to the Cemfjord's capsizing"
1025:
1176:"Pentland Firth tidal turbine project given consent"
1016:
1088:"Salmond hails Pentland Firth Europe's powerhouse"
993:
408:, according to a Nordic tradition recorded in the
386:that resulted in the death of eight crew members.
252:border the firth to the north and are part of the
987:
985:
1295:
1020:; MacGregor, Kerr; Jones, Clifford (July 2006).
96:
1152:. MeyGen Ltd. 16 September 2013. Archived from
474:. This has taken on a political dimension. The
428:folklore. The name of the race is derived from
176:The name is presumed to be a corruption of the
1139:, 28 October 2010. Retrieved: 4 November 2010.
982:
396:Map of the Pentland Firth and associated lands
1069:(32). Scottish Renewables. Archived from
1024:. Scottish National Party. Archived from
1050:
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943:. Cambridge : D.S. Brewer. p. 120.
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389:Some of the principal tidal races are:
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509:, received operational lease from the
287:, on the western fringe of the Firth.
244:group are in the east. The islands of
60:
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1134:Major Scottish tidal project unveiled
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968:. London: B.T. Batsford. p. 32.
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1124:BBC News. Retrieved 26 October 2008.
148:, meaning the Orcadian Strait) is a
1193:Lewis, Michelle (4 February 2020).
966:The folklore of Orkney and Shetland
13:
1238:
1224:The Celtic Place-Names of Scotland
1104:Carrington, Damian (10 July 2013)
524:
14:
1335:
1258:
1122:"Major tidal power plan revealed"
1006:from the original on 25 May 2022.
890:
676:"Britons" in this case means the
199:. One version of the 9th-century
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941:Dictionary of northern mythology
164:. Despite the name, it is not a
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1319:Renewable energy in Scotland
629:Renewable energy in Scotland
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7:
964:Marwick, Ernest W. (1975).
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341:operate on this route from
295:In the West the ferry from
225:in the west to Old Head on
10:
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1067:Scottish Renewables Review
1060:"Small Country Thinks Big"
436:, meaning "the Swallower".
95:
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28:
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1039:14 October 2013 at the
667:Watson (1994) pp. 62–63
501:, a consortium of ARC,
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1324:Orkneyinga saga places
1282:28 August 2006 at the
1277:Pentland Firth - Tides
1226:. Edinburgh; Birlinn.
939:Simek, Rudolf (1993).
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1222:Watson, W. J. (1994)
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1273:at Wikimedia Commons
1182:. 16 September 2013.
1094:. 29 September 2008.
848:58.69667°N 3.11667°W
785:58.64528°N 3.02306°W
722:58.67250°N 3.37528°W
624:Gulf of Corryvreckan
322:opened 28 July 1874
152:which separates the
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1304:Straits of Scotland
1031:on 3 December 2006.
882:for John o'Groats:
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337:itself. At present
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1137:New Civil Engineer
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202:Historia Brittonum
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1058:(November 2006).
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1154:the original
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1110:The Guardian
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586:Minke whales
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240:. The small
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137:
135:
119:58.7°N 3.2°W
73:Location in
18:
851: /
788: /
725: /
611:leatherback
551:common seal
472:tidal power
466:Tidal power
384:MV Cemfjord
379:tidal races
372:Tidal races
215:Dunnet Head
122: /
97:Coordinates
1298:Categories
1251:by Adcock
1217:References
1204:4 February
1160:12 October
1108:. London:
975:0713429992
839:03°07′00″W
836:58°41′48″N
776:03°01′23″W
773:58°38′43″N
713:03°22′31″W
710:58°40′21″N
426:Shetlandic
285:Thurso Bay
124:58.7; -3.2
1309:Caithness
873:longitude
816:longitude
753:longitude
694:longitude
678:Brythonic
597:Gills Bay
566:Gills Bay
561:Porpoises
555:grey seal
430:Old Norse
406:whirlpool
343:Gills Bay
305:NorthLink
301:Stromness
297:Scrabster
209:Geography
186:Edinburgh
178:Old Norse
172:Etymology
158:Caithness
1280:Archived
1199:Electrek
1180:BBC News
1037:Archived
1004:Archived
885:ND379735
869:Latitude
812:Latitude
800:ND405733
749:Latitude
737:ND202767
690:Latitude
618:See also
572:Dolphins
422:Orcadian
311:Hamnavoe
162:Scotland
89:Scotland
85:Location
75:Scotland
1034:Alt URL
766:point:
607:Turtles
449:⁄
261:Britain
197:Kintyre
193:Pictish
107:58°42′N
1230:
972:
947:
926:
908:27 May
655:
601:Stroma
543:Stroma
499:MeyGen
434:Svelgr
416:named
414:gýgjar
335:Orkney
327:Stroma
318:. The
316:Thurso
277:Thurso
234:Stroma
150:strait
110:3°12′W
41:Orkney
1253:et al
1074:(PDF)
1063:(PDF)
1029:(pdf)
635:Notes
547:Swona
538:Seals
410:Eddas
331:Swona
238:Swona
184:near
166:firth
156:from
1228:ISBN
1206:2020
1162:2013
970:ISBN
945:ISBN
924:ISBN
910:2019
825:for
762:for
653:ISBN
505:and
424:and
333:and
329:and
279:and
248:and
236:and
136:The
91:, UK
476:SNP
349:on
345:to
309:MV
299:to
283:in
269:Mey
246:Hoy
223:Hoy
39:in
37:Hoy
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
