*History of British Buoyage

The earliest aid to navigation must have been a withie planted in the mud but the buoy would have been the next. Such buoys have existed for centuries. Different methods of marking them developed causing confusion: from the 1800s onwards, growing trade, steamships, ship and buoy lighting technology increased the problem: it remained unresolved, due to politics and war, until the late twentieth century.

Introduction

So, for centuries, navigation buoys have helped mariners avoid hazards and inform them of their position. The requirements of a floating barrel, chain or rope and a stone sinker were available since antiquity1For chains see ‘Caesar • Gallic War — Book III’. For Cooperage see Wikipedia Cooper (profession).

Shape, colour and topmark were the first characteristics used to differentiate buoys: authorities made independent choices, and so, for centuries, contradictory systems, both nationally and internationally, confused Mariners. There were many attempts in the late nineteenth, and first half of the twentieth century to achieve a common system but little success. Some of the proposals now seem perverse.

There must have been systems in the Eastern world but these are not discussed, nor are fixed navigation marks such as lighthouses, beacons or lighthouses.

The simple, elegant IALA system has been in effect since the 1980s: it has six types of buoy: Lateral, port and starboard; Cardinals; Safe Water; Isolated Danger; Special Marks and, since 2006, Wreck marks. Other than the colour difference between systems A and B, the scheme is consistent Worldwide.

So, how did the IALA develop; what preceded it in Britain; what logic underlies it, and what were the key developments along the way?

Early Buoyage

In the Western World, the practice of placing buoys can be traced to the Hanseatic League which traded across the Baltic and North Sea from the eleventh century.

The Low Countries have similarities to England’s East Coast with sandbanks and tidal streams. The Baltic, however, has negligible tides and many rocks and islands. Britain had few buoys until the nineteenth century and most likely absorbed some of the ideas from ports around the Wash2Hanseatic League and King’s Lynn with Hanseatic links as well as Europe.

The Hanseatic League in 1400
Droysen/AndrĂŠe, CC BY-SA 3.0 , via Wikimedia Commons
2019 Inverted Wooden buoy poss found in Deben
2019 Inverted Wooden buoy poss found in Deben

To aid navigation, beacons, perches (withies), and buoys, known as ‘tonnen’ or ‘seetonnen’, were laid. The buoys would have been either barrels or conical wooden casks attached by iron chains to sinkers. There is a small example of this type at Woodbridge Museum although its origin is unknown. Cooperage techniques were used in their construction, they were often painted with pitch and so were black. In Europe, later on. white was used for port but soon became fouled. Chained at the apex, they would have floated on their side, in the manner depicted on old charts. Sometimes, a name or number was painted on the circular face or on top marks or flags. In time, conical versions, or nuns, were developed which allowed for more discrimination.

Another name for the ‘tonnen’ was the Dutch or French ‘boeie’. It was this the English adopted. It can be pronounced as ‘boy’, or in the American style as ‘buoy’. Perhaps both are wrong as it may well have been pronounced ‘bwoy‘ in the early nineteenth century3Pronounciation of buoy – see Benjamin Humphrey Smart, A Practical Grammar of English Pronunciation: On Plain and Recognized Principles, Calculated to Assist in Removing Every Objectionable Peculiarity of Utterance Arising from Either Foreign, Provincial, Or Vulgar Habits, Or from a Defective Use of the Organs of Speech … : Together with Directions to Persons Who Stammer in Their Speech : Comprehending Some New Ideas Relative to English Prosody (John Richardson … and J. Johnson and Company, 1810).. . The word ‘tonne’ for barrel lives on in tons and tonnage.

Port hand mark with downward birch twigs
Deutsch Wikipedia

In Europe, the practice developed of marking channels with ‘brooms’ of birch twigs pointing down to the north and up to the south, although there does not seem to have been complete consistency in whether they indicated safe water or a hazard. This inspired the north point up convention for the cones used on beacons and cardinals today. It also was generally associated with starboard marks.

1920s Beacons on the Deben
from Meesum’s Rivers and Creeks

Tree trunks were commonly used as ‘spar’ type buoys, in the Baltic and United States where timber was plentiful. In these cool climes, the marks were often removed in Winter.

Trinity House Founded

The foundation of England’s Trinity House in 1514, by Henry VIII was a key development although the number of buoys in the Thames Estuary grew slowly, reaching only sixteen by 16844IALA AISM. ‘A History of Floating Aids to Navigation by Adrian H Wilkins’. and a ‘buoy boat’ was not commissioned until 1742. Later on, Hull had its own Trinity House, Scotland the Northern Lighthouse Board and Ireland its Ballast Board, which became Irish Lights. The major areas of interest are the Thames, Humber, Forth, Tay, Clyde, Mersey, Belfast and Bristol Channel. Of these Trinity House managed the Thames and Bristol Channel.

Eighteenth Century

Dunkirk laid Black/Starboard, White/Port channel buoys in 1776.

This 1787 Coasters Companion shows a variety of marks in the Thames Estuary with black, red and white, being assigned to port or starboard, seemingly at random. There was no direction of buoyage.

1787 Coasters companion extract

The 1790 Chart shows about thirty buoys in the Thames Estuary, as described above. White was hard to spot. None were lit at this time although there were some lightships.

Early Nineteenth Century

An extract from an 1845 chart of the Estuary shows several styles. Most probably they were deployed such that, if a rough location was known, the buoy would be sufficiently distinctive to be identified from the pilot5See the 1844 Coasters Guide where buoys are learned by rote.The 1847 Sailing directions for the river Thames, from London enable the navigator to plan a route buoy to buoy. in much the same way as Safe Water marks today.

Buoyage of Liverpool and the United States

Liverpool was Britain’s gateway to the west and, with the industrial revolution forging ahead, traffic was growing rapidly. Lt Henry Mangles Denham6Henry Mangles Denham and A Naval Biographical Dictionary/Denham, Henry Mangles7Denham had surveyed the Channel Islands and Coasts of France. was sent to survey the port in 1833 and made recommendations for the buoying of the channels8In the 1799 and 1807 Pilot Liverpool had a system of cones to starboard casks to port91839 British Channel Pilot – p118 Liverpool – The Buoys in the channels are so arranged, that on entering, those painted red are to be left on the starboard side, and those painted black on the larboard. Buoys striped black and white, are laid upon intervening banks or flats. Superior can- buoys with perches are placed at the elbows or turning points of the principal channels. Each buoy bears the initial of the channel it occupies; thus , F , signifies Formby Channel; C , Crosby Channel ; H. F , Half tide Swashway ; N , New Channel; H , Horse Channel ; R , Rock Channel ; H. E. , Helbre Swash; B , Beggar’s Patch ; L. Hoyle Lake ; & c . The buoys are likewise numbered in rotation , No. 1 denoting the outer or seaward buoy of its channel the letter indicates.. iverpool, in 1807, had conical buoys to starboard and casks to port. By 1839 Lt. Denham had set the buoyage so that starboard/cones/red and port/cans/black. He also set buoys to mark middle ground buoys at the end and sides. Channel buoys were named and numbered. His work there was to form the basis for other systems. He may have been influenced by the French system10The French system from 1839 was red cans to starboard and black cones to port with naming and numbering, there were various striped buoys and topmarks. It is unclear when this started.. As the United States carried out a great deal of its trade via Liverpool in 1851 it adopted the ‘red, right returning’ system, with red to starboard and black to port11The US in any case mostly used spar or cask buoys..Scotland adopted it in 1857.

This was the critical choice that eventually led to the division of the World into IALA A and B. Lit buoys were not to appear until the 1880s, but it could be seen that ship lighting, logical when meeting vessels, would conflict with future buoy lighting colours especially as there would be no convention on fixed versus flashing. It took two more decades to act on the Commission’s findings although the report is a valuable historical resource.

Collision Regulations and Ship Lighting: 1840s

As the Industrial Revolution progressed in the nineteenth century, not only was sea traffic growing with trade but the age of the steamer had dawned. Britannia ruled the waves. Collisions, wrecks and groundings were commonplace.

The 1840s saw the introduction of British Collision Regulations12Colregs see Bahr, Rudiger. ‘The Development of Regulations for Preventing Collisions in Inland, Inshore, and Open Waters of the UK during the First Half of the Nineteenth Century’. Thesis, University of St Andrews, 1998. https://research-repository.st-andrews.ac.uk/handle/10023/14084. and then, in 1848, the Admiralty required steamers to display lights, in the form we know today, red to port, green to starboard. As ships conventionally passed port to port and red meant danger, this was logical. These regulations remained, with small alterations, to the present day.

Taking Stock: The 1861 Royal Commission

In the mid-nineteenth century, marine navigation was chaotic: buoy colours and shapes were not standardised and they were unlit. So, in 1861 Royal Commission was formed on the state of British lights and buoys. Trinity House, the Lighthouse Authority for England, managed over three hundred buoys in England. However, across the U.K. management of buoys was divided between three or four Lighthouse authorities, the Admiralty, and local authorities. Each operated its own, sometimes conflicting, system. There was not even consistent vocabulary for describing buoy shapes: cones, nuns, spirals etc..

So, about 140 different organisations were managing around 1100 buoys in the United Kingdom: 55% were managed by Local Authorities; Liverpool and the Clyde being the largest. Trinity House had a plan of black or red cones to starboard, striped or chequered cans to port although only used it on new buoys131861 Extracts from the Report of Her Britanic Majesty’s Commissioners, appointed to inquire into the Condition and Management of Lights, Buoys, and Beacons, Submitted March 5, 1861,; Liverpool14Liiverpool in the 1815 survey by George Thomas has cask buoys at key points15Liverpool Buoyage see page 130 Admiralty hydrography dept, Sailing Directions for the West Coast of England, West Coast of England Pilot. Admiralty Notices to Mariners, 1870. had adopted red cans to starboard, black cones to port for the Mersea, Scotland had a similar scheme although Hull16Hull- see 1861 Report of Her Britanic Majesty’s Commissioners, appointed to inquire into the Condition and Management of Lights, Buoys, and Beacons, Submitted March 5, 1861 page 319 – XXVII. All the buoys on the south side of the Humber are coloured red, with a horizontal white stripe, and numbered 1 to 12, commencing with the sand hale buoy, and terminating with the westerninost buoy on the upper middle, opposite the town of Hull. The buoys on the north side are all black, and numbered 1 to 12, commencing with the outer binks buoy, and terminating with the upper hebbles buoy. The buoys on the middle sands or shoals in the lower part of the Humber are all chequered black and white. The hook buoy on the lower middle is painted white, and marked “book middle.” had the opposite, and so on. had black to starboard, red to port and chequered B/W middle grounds

A ‘Proposed Uniform Code’ based on the Liverpool system was submitted to the Commission by Captain E.J. Bedford although this does not appear to have been adopted, it was claimed to be similar to the French system171874 Sailing Directions for the English Channel: The south coast of England, and general directions for the navigation of the Channel. The north coast of France, Parts 1-2 pp236 – BEACONS AND BUOYS . The following is the system of Buoys and Beacons on the coast of France : – When entering a channel from sea all buoys and beacons painted red with white band near the summit must be left to starboard , and those painted black to port . That part of the beacon which is below the level of high water , and all warping buoys are coloured white . The small rocky heads in frequented channels are coloured in the same way as the beacons , when they have a surface sufficiently conspicuous . Each beacon or buoy has upon it in full length or in abbreviation , the name of the danger it is meant to distinguish , likewise its number , commencing from sea- ward , and thus showing its numerical order in the same channel . The even numbers are on the red buoys , and the odd numbers on the black buoys ; the buoys and beacons coloured red , with black horizontal bands are named , not numbered .. By 1890 Liverpool conformed to the Uniform System181891 Sailing Directions for the West Coast of England – BUOYAGE . – The uniform system is adopted in buoying the several channels to the Mersey , and is such that , coming upon a buoy in the night the seaman may know by its shape on which side of the channel it is situated . An uniform system with respect to colour is likewise maintained as far as circumstances will allow . Thus , when inward bound , conical buoys are to be left on the starboard hand , can buoys on the port hand , and spherical buoys on either hand ; the conical buoys are painted red , can buoys black , and spherical buoys with horizontal stripes . On the buoys of every channel are painted the initial letter of the channel , with a number , the numerals being arranged in consecutive order , reckoning from seaward ; thus a conical buoy , marked Q. 1 , or a can buoy Q. 1 , denotes , respectively , the outer buoy on either side of Queen’s channel , the next buoys inward being marked Q. 2 , and so on for other channels . Fairway buoys bear the initial letter of their channel , and ” Fy . , ” and have distinct characteristics of form and colour ..

Captain Bedford’s Proposal from the 1861 Report

A key development was the introduction of buoys made of iron. This was the enabler for larger, more durable marks and greatly increased the range of shapes available. It was also a necessary precursor to the storage of fuel that would needed for soon for lighted buoys.

Bell buoys appeared in 1860 and whistles twenty years later along with the first lights. The images, from an 1861 report, show some of the types in use at the time, buoys could be cans or cones in black, red or white, with horizontal and vertical stripes and with or without various top marks:

See Charles Babbage and Lighting, not implemented but interesting.

By 1877 the Ovens buoy on the Thames was trialled with the Pintsch gas lighting system19Pintsch gas lighting system. Soon these could run for over three weeks unattended and were deployed in key locations.

The 1882 Trinity House Royal Conference

Twenty years passed before the problem was addressed by the Royal Conference at Trinity House in 1882, chaired by the Duke of Edinburgh.

British Uniform Buoyage:

This produced the ‘Uniform System of Buoyage’201883 Nautical Magazine VOLUME LII.-No. VIII. AUGUST , 1883 . see page 573 for the UNIFORM SYSTEM OF BUOYAGE.. Shape rather than buoy colour was the key characteristic with colours optional. Cones to be to starboard, all of one solid, unspecified, colour and cans to port in a different colour, possibly patterned. The top marks could be a globe, can, diamond and triangle. The direction of buoyage was the flood and spherical middle ground buoys were included as well as green wreck marks. By 1890 the Thames Estuary had 177 buoys plus eight gas-lit buoys introduced a decade earlier.

Middle Ground Buoys

The term ‘middle-ground’ had been in use since at least the seventeenth Century21See A Description & Plat of the Sea-Coasts of England, 1653 to describe a bank with a channel on either side. Middle ground buoys appeared in the Bristol Channel between 1839 and 186822See 1839 Pilot and 1868 Bristol Channel Chart. Middle grounds were in Bedford’s proposal so may have been used in Liverpool and possibly France., the Thames Estuary between 1852231852 A new chart of the River Thames inc. Harwich and 1907 Reynold’s new chart of the Thames Estuary see Oaze & Girdler. and there was one at Hull in 1870.

This scheme was largely adopted and endured, more or less, until 1977, nearly a century. All British buoys were laterals at this point and, as it became possible to place buoys further out to sea, ambiguity arose. This was also a period of innovation, one example was the ‘Refuge Buoy‘.

Attempts at Worldwide Standards: 1889 & 1912

Britain was to become, until the 1960s, the pre-eminent maritime power and much of the Empire would follow her lead: also, France and North America were broadly consistent. European countries had a variety of systems with many Baltic states having a compass or cardinal system unlike today’s.

Following the 1861 Royal Conference, there were attempts over the next sixty years to reach a worldwide agreement on a common system. The main ones were Washington in 1889, St Petersburg in 1912 and Geneva in 1936. These had few tangible results.

1889 Washington International Marine Conference

This conference aimed to build upon the Royal Conference and achieve some international agreement. It took the stance that buoys should be distinguished by colour and number, rather than shape, partly on the basis that colour was easier to change. It recommended red, ideally conical, to starboard and port, ideally can, black or multicolour. Middle ground buoys were to be horizontal stripes. The U.S., France and Spain adopted this scheme and it was not inconsistent with the British scheme, although the British involvement does not appear to have been wholehearted. North America was to retain this scheme throughout. The conference was wide-ranging and included lighting, signals, collision regulations, bearings and safety at sea. There was an attempt to agree on a compass, or cardinal, system but judging by the systems in use in the Baltic in the early twentieth century this was not widely adopted.

At this point, it should not have been difficult to agree on red cones to starboard and black cans to port but the chance was lost.

1912 St Petersburg Conference

This strange conference was called by Russia and France with the invitation to the U.S. going out at the last minute, and none to the U.K. and Canada. It reversed the Washington system with red cones to port and black cans to starboard. However, only three countries adopted the resolutions and this strange affair must have caused more problems than it solved. The French did not implement this scheme despite being a key player.

Lighting Creates a Problem

By the 1910s, there were many lit buoys which could be confused with ships’ lights. The St Petersburg scheme, if adopted, would have resolved the issue of harbour entrance lights, since it had red to port which was the same as lighting for ships (introduced by the Admiralty). The earlier Washington scheme of red buoys to starboard conflicted with ships’ light colours.

Around this time there was a major advance in buoy lighting with Gustaf DalĂŠn’s acetylene system. This produced a far brighter light and was accompanied by an occulting mechanism. Dalen was awarded a Nobel Physics Prize for this work: Albert Einstein had to wait. Dalen’s system was still in use in the 1950s and possibly later.

Also, a development worth mentioning is the ‘Sound Signalling System‘ which enabled ships such as Ocean Liners to fix position by underwater bells.

Pre World War Two British and European Systems

British Uniform Buoyage

The pre-war British system dated back to 1882. Trinity House emphasised buoy shape: single colour red or black cones to starboard, parti (multi) colour cans to port: the emphasis was on shape and topmark, not colour. Scotland had red cones to port and black cans to starboard24See United States Hydrographic Office, British Islands Pilot: East Coasts of Scotland and England (U.S. Government Printing Office, 1915) page 34 – Coloring of buoys . – In carrying out the above uniform system on the east coast of England the colors adopted by the Trinity Houses of London and Newcastle are whole colors on the starboard hand and parti – colors on the port hand ; in Scotland starboard hand buoys are painted red and port hand buoys black. Scotland and Liverpool were more consistent in having red cones to starboard. This system was to remain in place, with some swapping of red and black, until 1977. The key elements were:

Lateral and Middle Ground buoys

Lateral systems generally were defined by the flood stream to a port but this sometimes caused ambiguities. Spherical, striped, middle-ground buoys were used to mark sandbanks, often with side laterals.

The extract from the 1907 Reynolds Chart of the Oaze Bank shows middle-grounds deployed. They were supposed to mark the inner and outer extremities but, in this case, failed to differentiate. Note that they are gas-lit and occulting – the latest technology.

1907 Reynolds Chart extract of the Oaze

This chart shows, perhaps, two dozen gas-lit buoys in the southern part of the Estuary: only Whitaker and Knoll are gas-lit north of the Crouch. In England. There were still a few wooden buoys in place in the 1920s, before Second Wold War, the main marks were:

British System from 1938 Admiralty Manual of Navigation
British System from 1938 Admiralty Manual of Navigation – Overview

European Systems

French buoys were similar to the British in the early twentieth century, note the familiar top marks:

Extract from 1938 Admiralty Manual of Navigation

The British, American and French systems did not use cardinals, preferring middle-ground marks: all had red to starboard, although England was less rigorous on colour.

Baltic Cardinal Buoys

The lateral/cardinal systems used in the Baltic related to compass bearings and, some indicated the direction of the danger, not the safe water. The examples are from the 1930s. The emphasis was on compass bearing rather than flood stream, because of indefinite tides.

First, the Swedish version, which combines cardinals and laterals and looks daunting:

Extract from 1938 Admiralty Manual of Navigation

The German scheme was different and had laterals with red cans to starboard, and black cones to port, note the cardinal top marks which were to live on in the IALA system:

Extract from 1938 Admiralty Manual of Navigation

Inter-War Attempt at a Common Standard: 1936

The League of Nations, created after the Great War, held Conferences to produce a Uniform System of Buoyage. This recommended red cans to port with red lights, even numbers, black cones to starboard, white lights and odd numbers. The upwards cone was standardised for starboard and square can for port top marks. Chequer patterns were included, perhaps for the British. The direction of buoyage was usually the flood stream.

1937 League of Nations Uniform Buoyage Laterals

The scheme had a complex set of top marks. The North and South cone shapes could be replaced by ‘brooms’ of twigs or branches as used in minor channels. Additionally, there were green marks for wrecks and middle-ground spherical buoys. The green light was reserved for wrecks and Cardinals were included. The many variations reflected the need to keep all parties satisfied.

1937 League of Nations Uniform Buoyage Cardinals

The complex cardinal system could be confused with laterals and lacks the economy and clarity of the IALA scheme. The cardinal indicates the direction of the danger, not safe water251936 Geneva Cardinals – ‘The cardinal system is generally used to indicate dangers where the coast is flanked by numerous islands, rocks and shoals, as well as to indicate dangers in the open sea. In this system, the bearing (true) of the mark from the danger is indicated to the nearest cardinal point.’.

Britain’s acceptance was conditional on that of her North Sea neighbours and, although they had mostly accepted, Britain did not adopt the system. The U.S. did not ratify this noting that it would have to reverse the colours of over 22,000 buoys, approximately 40% of the World’s stock. The Uniform System conflicted with those of the UK, US, and France which was a recipe for failure although it had the characteristic that the buoy colours were almost the same way around as the ships’ lights.

The Second World War brought progress to a halt.

Post World War Two, Britain changes sides

The end of the War was an opportunity to update systems. In the U.K. and Europe, many buoys had been removed and maintenance ignored. Charts of the time show that the Second World War left many green wreck buoys around our coasts. They also show that there were inconsistencies: for example, by 1948 Harwich had black cones to starboard, and red cans port but the River Orwell had red cones to starboard and black cans to port. Lights to starboard were white, green was still used for wrecks. The use of middle-ground buoys was common, there were no cardinals. Around 1950 these colours were swapped to become consistent with the Uniform System of Buoyage: the change happened quickly in the Thames Estuary.

Of local interest is that, in 1950, six buoys were placed in the Waldringfield Fairway from Methersgate to the Rocks on the River Deben, these probably replaced the wooden beacons. New Trinity House rules were to change all channel markings to Black to Starboard, and Red to Port. Waldringfield adopted this scheme, the buoys being positioned by the appropriately named Mr Nunn, although Woodbridge declined, their buoys were recorded as being the other way around, which may have caused confusion at Methersgate26See Deben Beacons.

During the nineteen fifties and sixties, major advances in technology occurred. Steel had long replaced iron and there were trials of GRP and plastic for buoy bodies. There were major developments in lighting and electronic aids that provided yet more options for diversity. Many methods for powering buoy lighting, sound and electronics were tried from seawater batteries to radioactive isotopes.

The Varne Disaster

So, post-war, countries had adopted variants of the British or the League of Nations schemes. In general, however, everyone, more or less, carried on as they were. For example, Denmark had black to starboard, and white to port, while Holland and Belgium, had the opposite. There were inconsistencies of colour around Britain up to at least the 1950s. However, War intervened so confusion continued.

An IALA committee was established in 1967 to address the confusion. Although it agreed on ODAS boys and the marking of beaches little real progress was made. The US and Canada made it clear that they were not going to change their buoyage which was based on the 1892 Washington System. They had a simple lateral system with red to starboard and no cardinals.

On the night of January 11th 1971, the outbound tanker Texaco Caribbean collided with inbound cargo vessel Paracas near the Varne Bank. She exploded and broke in two, Paracas was damaged but eventually towed to port. The next night outward bound MV Brandenburg struck the wreck and soon foundered just two miles away. By late February many green wreck buoys had been laid and a ‘Wreck Light Ship’ put in place. Despite this another cargo vessel, the outward-bound Niki, struck the wreck and sank. All three wrecks had a considerable loss of life. It should be noted that, in this era, there was an optional traffic lane scheme but ships were free to sail wherever was convenient and there was no RADAR surveillance as there is today. The three incidents were a catalyst for the formalisation of the Traffic Separation Scheme (TSS) within the Straits of Dover

Progress: Captain Bury takes the Chair

This emergency focussed the minds of the IALA committee but by 1973, there was still no agreement, although cardinals had been abandoned in an attempt to achieve unification. At this point, Captain John Bury was appointed to chair the committee. This problem had festered for over a century so a new approach was needed. He determined to cut losses and start from the first principles using logic and set the principle that buoys should convey their information on a pitch-black night. This implies the use of light colour and probably, rhythm.

Laterals

Bury adopted the principle that the lateral system should be oriented with a conventional direction of buoyage and not necessarily the flood tide which caused ambiguity. The colour and lighting of laterals were addressed by assigning red and green exclusively to them. The use of green solely for wrecks was seen as a waste of colour. Numbering was to be in the direction of buoyage with even or reds and odd on greens. All lights would flash, this had not been the case meaning that fixed and floating lights could be confused. The new lateral system was set up in 1974 as a trial in the Knock Deep and found satisfactory. Today trials are conducted East of Cork Sand from Harwich.

From THE BACKGROUND TO IALA BUOYAGE SYSTEM “ A ” by Captain J. E. BURY 1978

Specials

Larger tankers needed deep water channels, as at Southampton. These could not be marked unambiguously with laterals. Consequently, yellow marks with yellow lights were introduced as laterals. This enabled normal shipping to follow the usual reds and greens to leave the deep water clear.

Middle Ground to Cardinal

At sea, an isolated lateral could be ambiguous. Middle Ground buoys failed the pitch-black night test as they were distinguished by their spherical shape so were abandoned in favour of cardinals. The development of the cardinal system was interesting. Various, inconsistent, systems had been used in the Baltic but indicated the bearing from the danger lay, not safe water. The German topmark system appears to have been co-opted. The Swedish system of cardinals was quite different. The 1937 Uniform System would have failed the pitch-black night test. Yellow was adopted to distinguish cardinals from laterals and the principle of operation was changed to indicate safe water not danger. It would be the responsibility of the navigator to recognise the special mark and assess the danger from a chart.

The cardinal lighting sequence was constrained by technology and arrived at as much by accident as design. To meet the pitch-black night test, distinctive colours or rhythms were needed. Three sequences for the cardinal directions, including VQ for North and Gp Fl(3) for S were proposed but the fourth sequence proved difficult to find. It was difficult to flash a definite number and long flashes were wasteful of gas. Eventually, the gas lighting technology was developed to produce up to eleven definite flashes and the sequence N-VQ, E- Gp Fl(6)+Long, S-3 and W-9 was established. At this point, somebody had an epiphany and realised that small changes would result in the clock face we now know. The Black/Yellow day colour system was then added, this simple, logical scheme provides redundancy for the top marks. It was sea-tested in the Baltic at night in a force seven and found to work well. The replacement of spherical middle ground buoys with pillar cardinals must have left many sphericals spare albeit some could be re-used as safe water marks.

Isolated and Safe Water

An Isolated Danger mark would only be used where the water was navigable all around, the chosen scheme is similar to the French version. A Safe Water mark would indicate safe water in a channel. These and cardinals used the white light in different sequences.

A Unified System, of a Sort

The IALA A system was agreed upon in 1977 and implemented at different speeds by the signatories with the U.K. being an early adopter, the new system is shown on a 1975 chart. The U.S. and Canada had been involved in the process and were soon to agree and adopt the similar IALA B system, with reversed red and green, in 1980. The Emergency Wreck Marking Buoy was introduced in 2005. Between 1977 and 2006 new dangers such as wrecks were marked by cardinal and special marks as green had been allocated to lateral marks.

The IALA A system of buoys has five basic shapes: can, cone, sphere, pillar and spar. There are six colours: Green, Red, Black, Yellow and Blue. The three basic patterns are solid, vertical stripes or horizontal stripes. To cap them, there are five top marks: Point up, Point down, Can, Sphere and X. Finally, lights can be green, red, yellow or blue with some sequence of flashing, no lights are fixed.

So, as should now be apparent, the system, which today seems so simple and logical, had a longer and more torturous development than one would think. Future developments are likely to be in the electronic, virtual realm: let us hope that we retain the physical buoys for many years to come.

Related

World War Two Air Sea Rescue Buoys or Floats

Submarine Sound Buoys

Rescue or Refuge Buoys

Bouy lighting – Nobel prize

Sources

Footnotes

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