THE REAL MAP OF IRELAND
from the bottom up
The Marine Institute displayed the Real Map of Ireland featuring the breath taking contoured map of Ireland‟s 220 million acre underwater territory, three dimensional computer model and charts of Irelands Bays and a close look at the history of charting Galway Bay from the bottom up - in a special exhibition on the quayside during the Volvo Ocean Race event.
The following information was provided by the exhibitors which can be used in class. For further information on the charting of Ireland‟s Bays see www.infomar.ie
1. THE REAL MAP OF IRELAND:
; The Real Map of Ireland shows the area of Ireland‟s marine resource which is
over 220 million acres – ten times the area of the land of Ireland.
; Historically the oceans of the world were considered to be without boundaries
and „free‟ to use for travel, trade and exploitation of resources. The Dutch first
made claim to the area of sea around land in the 1700‟s based on the concept of
the “three nautical mile” coastal limit. (This was based on the range of land-
based cannons to fire a cannon ball out to sea). Ever since then, countries have
laid claim and tried to exert control over parts of oceans that border their shores. ; In the 1960‟s the United Nations Convention on the Law and Sea (UNCLOS)
established a framework of agreed definitions that gave countries a way to
establish their claims. This was later established as international law in 1982.
o Territorial seas – 12nautical miles (nm) from the coast.
o Contiguous zones e.g. customs, immigrations, sanitary controls – 24nm
o Economic Exclusive Zone (EEZ) – 200nm
; The EEZ gives each country the sovereign right to explore, exploit, conserve and
manage living and non-living resources in the water and on the seafloor.
; The Law of the Sea allows for countries to make claims over shelf areas that go
beyond 200nm – e.g. if they can show that their continental shelf extends beyond
the established 200nm EEZ.
; The Real Map of Ireland shows the designated Irish Continental Shelf – see red
line on the map.
; This area includes one of the largest Exclusive Economic Zones (EEZ) in the
; The border of the Irish EEZ extends just beyond what is the „European‟
continental shelf. The designated Irish Continental Shelf is the area of Irish
underwater territory which extends beyond the „European‟ continental shelf line
200 nm from the shore.
; The Real Map of Ireland has been developed based on information gathered in
surveys such as the Irish National Seabed Survey (INSS). This survey began in
1999 and lasted for six years. It remains one of the largest seabed mapping
projects ever undertaken in the world.
; It has produced over 300+ paper based charts and some 11 Terabytes of digital
information. If you were to burn this information onto a DVD you would need
Further lesson plans on the Real Map of Ireland are available at
2. ADMIRALTY CHARTS / SOUNDING & LEAD LINES
; Most nautical charts produced by hydrographic offices worldwide now indicate
depths of the sea in metres. In the 1800‟s however, nautical charts used feet
and fathoms (units of six feet) to indicate the depths of the sea.
; Until recently, marine charts of Irish coasts had not been updated since the
1800s, when the task was undertaken by the British where a number of famous
seamen and hydrographers were involved.
; Captain Bligh famous for the “Mutiny on the Bounty” incident and later went on to
be the Governor of Australia charted Dublin Bay in 1800. The chart was
completed in 1803 and was considered the most accurate map of the bay well thinto the 20 century.
; Admiral Francis Beaufort, born in County Meath was famous for inventing the
Beaufort Scale in 1806. In 1844 he was responsible for sending Commander
George Bedford to survey the west cost of Ireland, where he was to remain at
work for fifteen years.
; Based on the surveys done in the 1800‟s and updated with more modern
information, the present admiralty charts of Irish waters are drawn up by the UK
Hydrographic Office. They are used today as navigation aids for shipping and
marine activities. The accuracy and updating of Irish charts and the maps of our
sea areas, have been debated for years.
; When we overlay an enlarged section of a modern bathymetric chart completed
recently by the INFOMAR survey onto an old Admiralty chart showing Galway
Bay in the late 1844 - 51 we can see how accurate the old methods of using
sounding lines and lead lines to gather information were, even though they were
; In the 1800‟s to measure the depth of shallow waters, boatmen used a
OM points. A fathom is a nautical unit of SOUNDING LINE containing FATH
measurement equal to
; Sailors didn't go around carrying rulers in their back pocket so they used their
bodies instead to measure distances. For instance, to measure a fathom, a sailor
would use a line / rope and pull it between his outstretched arms. The distance
from the tip of the left index finger to the tip of the right index finger was
approximately one fathom or six feet. (based on a person being six foot).
Markers using knots / coloured cloth or toggles between each fathom were then
used to indicate the depth of water.
; The well known drawing “The Vitruvian Man” by Leonardo da Vinci, depicts
historical units of measurement including the Yard, the Foot and the Fathom.
The distance from tip of nose to tip of an outstretched arm: one yard (three feet)
Length of human foot: one foot (12 inches).
; Water near the coast and not too deep to be fathomed by a hand sounding line
was referred to as “in soundings” or “on soundings”.
; The area offshore where water exceeding 100 fathoms in depth, too deep to be
fathomed by a hand sounding line, used a deep-sea LEAD LINE, (the heaviest of
3. MULTI-BEAM SONAR DEMONSTRATION ON LCD SCREEN / BAT:
; More recently the Marine Institute, the Geological Survey of Ireland and other research partners have been involved in charting the Irish waters using modern techniques such as using ship-mounted sonar equipment, aircraft-mounted lasers and satellite positioning.
; The Marine Institute runs two research vessels on behalf of the State called the RV Celtic Explorer and the RV Celtic Voyager. These vessels, along with other ships
have been used to survey the Irish waters.
o The RV Celtic Explorer is used to survey the deep water territory using
mounted multi-beam sonar equipment.
o The RV Celtic Voyager and aeroplanes have been used to chart the shallow
waters and inlets around Ireland using both echo sounders (multi-beam)
and airborne laser surveying (LiDAR) equipment.
o The vessels work 24 hours – day and night. Staff work in 12 hour shifts.
; To find out what is lies beneath the sea a MULTI-BEAM ECHO SOUNDER
SYSTEM and a LiDAR (Light Detection and Ranging) system are used.
o The multi beams works similar to how a Bat uses echo‟s to find its way when it
is flying in the dark. Because Bats are blind they rely on sound waves to find
their way. The sound waves sent out by the Bat hit the object in front of them
and bounce back i.e. so they sense trees, mountains and walls. o A Multibeam echosounder works in a similar way. From the bottom of the
vessel hundreds of sound pulses are sent to the bottom of the seabed in fan
shaped beams i.e a swath. The multibeams hit the seabed and then are
transmitted like echo‟s back to the vessel.
o The width of the swath is determined by the depth of the water. For example if
the water is deep there is more spread in the swath. If the water is shallow the
swath width is reduced. Therefore charting the deep sea only took
approximately just over six years. To complete the inshore areas around
Ireland is predicted to take up to 20 years.
o The information which is collected by special equipment on the vessel is then
processed and worked on to make different types of charts.
o Other factors have to be taken into account that can affect the overall
measurements such as tides, temperature, salinity and the pitch and roll of the
vessel. Note that sound travels at different speeds depending on the
temperature and salinity of the water. These have to measured and taken into
account with the processing.
o LiDAR is a remote sensing technology that uses laser beams of light to
measure the distance from a LIDAR sensor to distant objects. Its operation is
similar to how mulitbeam echosounder measures distances underwater using
o A LIDAR sensor, mounted in a plane, is flown over the area to be imaged. The sensor sends out a series of laser pulses toward the Earth's surface. Each laser pulse bounces off objects on its journey toward the ground and returns skyward toward the sensor. The LIDAR sensor measures the time it takes each pulse to travel to the ground or seafloor and back and uses this information to create a 3-D representation of the imaged surface
4. INFOMAR: CHARTS / LCD SCREENS SHOWING FLYTHROUGH AND BAYS
; There are a number of different types of maps and charts of the Irish waters that have been produced from the surveys completed by the Marine Institute, GSI, the Department of Communications, Energy and Natural Resources as well as international research partners.
; These maps and charts include:
o Bathymetry Chart shows the depth of the water. The different colours are
used which are matched to the legend at the side. Contours are also included
which are lines of equal depth. This is the same as what is done on land
o Shaded Relief Chart shows the seabed features and structural geology. On
the charts shadows are used to emphasise the features such as cliffs, banks
and troughs. Where areas are relatively flat no shadows are shown.
– i.e. refer to Real Map of Ireland
– the names of areas on the Real Map of Ireland include the
geology of the area e.g. Edoras Bank
– Galway Shaded Relief shows how the features of the limestone
steps continue under the water.
o Backscatter Chart shows the strength of the signal that is reflected back to the
vessel from the seafloor. (To help establish understanding of strength of
signals use analogy of throwing a ball against a hard floor v soft mattress –
what happens to the ball?)
- If the seabed is hard rock the signal is comes stronger and is
shown as a dark shade on the chart.
- If the seabed is sandy or muddy some of the signal is absorbed.
Therefore when it bounces back the signal is weaker. The colour
therefore is lighter.
- On the Backscatter chart you can also see the tracklines of the
vessel. Tracklines show how the vessel has to go up and down a
strip of sea like a lawnmower moves across a lawn.
- The backscatter charts now also show square areas where
samples were taken.
o Seabed Classification Charts shows the seabed type. It is similar to the
Backscatter but includes information using the samples showing the sediment
type (i.e. the different type of soils e.g. mud, gravel, sand, rock). These charts
are used to establish habitats in areas. We need to know what is under the sea
to be able to protect it and use it in a sustainable way.
; INFOMAR Current national coverage:
o 26 Bays are being surveyed
o There are also three priority areas including south west priority / south priority
and east priority. Priority areas have been selected for a combination of
reasons such as – renewable energy, shipping, marine leisure, safety at sea
and fishing resources, aggregates.
o Galway Bay was finished last year.
o This year INFOMAR has did some of Shannon in March. We are now in Dingle
surveying. During the year we will also be working on Dublin, Waterford /
Wexford (outer), Bantry block of south priority area, Killary, Donegal, Sligo,
; Multibeam echo sounders can pick up minor variations on the seabed floor such as
; (point out on the Real Map of Ireland locations of Shipwrecks of interest that are
within Irish waters.
; The Shipwreck Inventory of Ireland includes all known wrecks up to 1945. There
are approximately 10,000 records that have been compiled and integrated into the
o Wrecks over 100 years old and archaeological objects found underwater are
protected under the National Monuments (Amendment) Acts 1987 and 1994.
o Significant wrecks less than 100 years old can be designated by Underwater
Heritage Order on account of their historical, archaeological or artistic
importance as is the case with the wreck of the Co. Cork RMS Lusitania
located off Kinsale Head
o Under the legislation all diving on known protected wreck sites or with the
intention of searching for archaeological underwater material is subject to
o www.shipwreckscentral.com allows you to download information about
shipwrecks in the world including Irish waters.
SHIPS OF INTEREST ON THE REAL MAP OF IRELAND:
; RMS Lusitania:
- The RMS Lusitania was a British ocean liner torpedoed and sunk by the U-boat
U-20, on 7 May 1915.
- The ship sank in 18 minutes, eight miles (15 km) off the Old Head of Kinsale,
Ireland, killing 1,198 of the 1,959 people aboard. The sinking was instrumental
in bringing the United States into the war.
- It is considered the second most famous civilian passenger liner disaster, after
the sinking of the RMS Titanic.
- The British Government was quick to demonise the Germans for sinking a ship
carrying civilian passengers, while the German Government claimed that the
Lusitania was in fact an “armed merchant cruiser” with mountings for guns and
with a cargo of ammunition, which gave them a legitimate reason to torpedo the
ship without warning.
- The Bismarck (and her sister ship the Tirpitz) were considered the fastest, most
powerful battleships afloat in 1941 and Hitler‟s pride and joy.. However after a
nine day chase, which involved the sinking of England‟s famous battle cruiser
HMS Hood, the Bismarck sank during combat with the Royal Navy in the North
Atlantic in May 1941 after having been crippled by a torpedo from an old