The Irish Tide Gauge Network (ITGN) is a network of operational and historical 19 tide gauges around the coastline of Ireland. A tide gauge (also known as a mareograph or marigraph or sea level recorder) is a device for measuring the daily changes in sea level relative to a datum which in Ireland is known as the Malin Head Ordnance Datum. Within the Irish Tide Gauge Network there are various sensors recording longitude, latitude, date time, altitude, water level (m), water level to Lowest Astronomical Tide (m), water level to OD Malin (m), atmospheric pressure, sea temperature and data quality flags. The tide gauges are located on piers around the coastline of the Republic of Ireland. The first tide gauge became operational in 2006 with other tide gauges coming online during 2008, 2010 and 2017. Tide gauges feed data to the online databases in near real-time. Tide gauges support the monitoring and understanding of tides around the coastline of Ireland. The Irish Tide Gauge Network infrastructure has been supported by the Marine Operations team and data collected has been supported by the Oceanographic Services team within Ocean Science and Information Services of the Marine Institute (Ireland). Data complete for when tide gauges are operational. Incomplete time periods of data represent operational technical issue with the gauge(s).

Network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), dateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). Users of the download service can choose a gauge, time period, parameter(s) and output file type. Advanced downloads allow a user choose an Area of Interest (ie. more than one tide gauge) and depth value (ie. with tide gauge always '0') to download data. Real time data are also available from the FTP site, see www.irishtides.ie.

Tide prediction provides data that predict the ebb and flow of sea tides and any irregular variations in their heights. Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth. The times and amplitude of tides at any given locale are influenced by the alignment of the Sun and Moon, by the pattern of tides in the deep ocean, by the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry. Tidal predictions have been generated from measured data via the Irish National Tide Gauge Network and via modelled data from the Marine Institute operational hydrodynamic model. Tidal prediction was a calculation of future tide ranges based on available oceanographic parameters. Users can select a station and date and time within the next 2 years for the tidal prediction using the menus available. Water Level was sea surface height above local Lowest Astronomical Tide measured in metres. Tide predictions cover the coastline of the Republic of Ireland. Tide predictions have been completed for a day period up to 2 years into the future. Tide predictions for any period in the past can be requested. Tide predications have been derived from harmonic analysis of data measured at the tide gauges around the Irish coast (Irish National Tide Gauge Network Real Time Data). There are also predictions for a limited set of locations based on data obtained from the Marine Institute Regional Ocean Modelling System (ROMS) model (Ocean Forecasts). The tide predications have calculated the water level due to tidal forcing for a particular period in time. Storm surge due to atmospheric pressure and wind effects is not accounted for in these predictions. Tide predictions have been provided to understand the ebb and flow of tides particularly to support warning in an extreme weather event coastal flooding risk. Tide predictions have been run by the Oceanographic Services team within Ocean Science and Information Services section of the Marine Institute (Ireland). Data completed for any time period.

Description of measurements/samples, purpose for which they were collected, and the platforms/instrumentation and methods in collection GEO15_04 Irish Sea Drogheda 14m Globe DTM WGS 1984 projection Lowest Astronomical Tide (LAT). The GSI has been permitted to utilise the UKHO VORF (Vertical Offshore Reference Frame) sea surface model. This model allows the use of ‘GPS tides’ and the GSI has gridded this model to a 1km resolution around Ireland to 15km offshore for reducing all soundings to Lowest Astronomical Tide - LAT (VORF). By utilising ‘GPS tides’ there is no requirement to adjust for draft or squat as the water level is modelled over the seabed as measured to the WGS84 ellipsoid. This area was surveyed as part of the ongoing INFOMAR project (formerly Irish National Seabed Survey), a joint seabed mapping project between the Geological Survey Ireland and the Marine Institute. Survey work was conducted to standards and recommendations set out by INFOMAR, the International Hydrographic Organisation (IHO), the United Kingdom Hydrographic Office (UKHO) and the UK’s Maritime and Coastguard Agency (MCA). Please note the following: Data acquired prior to March 2011 were levelled to Lowest Astronomical Tide (LAT) using shifts derived from Proudman Oceanographic tidal model. Tidal height was derived using a network of offshore and onshore tide gauges. As such data are on average 0.54m deeper than the more recent UKHO Vertical Offshore Reference Frame (VORF) levelled data. We are currently updating the older datasets. Statement on the level of data processed and quality control, limitations on reliability INFOMAR bathymetry products generated to meet International Hydrographic Organization (IHO) standards to ensure gridded data positional accuracy in the horizontal (XY) and vertical (Z) frame. Arrangement of data Data has been processed and arranged into a GLOBE DTM grid using XYZ data. Spatial and temporal resolution of data within the dataset Image resolution is a 14m DTM grid. Length of time series Image created from data collected between 2015-10-01 and 2015-10-20 Amount of data expressed in number of stations, sites, observations, cores, months of recordings, miles of track or other units as appropriate Bathymetry image meets GLOBE DTM standard. Data provided under Creative Commons licence access and use conditions. Users of this data should provide the following attribution statement "Contains Irish Public Sector Data (Geological Survey Ireland; Marine Institute) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence"

The Ballycotton Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), dateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m), and sea surface temperature (celsius). The Ballycotton Tide gauge (51.828133,-8.000802) is owned and maintained by the Marine Institute and has been operational since 2010. None

The Ballyglass Harbour Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), DateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m), sea surface temperature (celsius), and Pressure (measured variable) exerted by the atmosphere (MB). The Ballyglass Harbour Tide gauge (54.2536, -9.8928) is owned and maintained by the Marine Institute and has been operational since April 2008. None

Description of measurements/samples, purpose for which they were collected, and the platforms/instrumentation and methods in collection RV Mallet 2019-2020 Legs Celtic Sea Cork 14m Globe DTM WGS 1984 projection Lowest Astronomical Tide (LAT). The GSI has been permitted to utilise the UKHO VORF (Vertical Offshore Reference Frame) sea surface model. This model allows the use of ‘GPS tides’ and the GSI has gridded this model to a 1km resolution around Ireland to 15km offshore for reducing all soundings to Lowest Astronomical Tide - LAT (VORF). By utilising ‘GPS tides’ there is no requirement to adjust for draft or squat as the water level is modelled over the seabed as measured to the WGS84 ellipsoid. This area was surveyed as part of the ongoing INFOMAR project (formerly Irish National Seabed Survey), a joint seabed mapping project between the Geological Survey Ireland and the Marine Institute. Survey work was conducted to standards and recommendations set out by INFOMAR, the International Hydrographic Organisation (IHO), the United Kingdom Hydrographic Office (UKHO) and the UK’s Maritime and Coastguard Agency (MCA). Please note the following: Data acquired prior to March 2011 were levelled to Lowest Astronomical Tide (LAT) using shifts derived from Proudman Oceanographic tidal model. Tidal height was derived using a network of offshore and onshore tide gauges. As such data are on average 0.54m deeper than the more recent UKHO Vertical Offshore Reference Frame (VORF) levelled data. We are currently updating the older datasets. Statement on the level of data processed and quality control, limitations on reliability INFOMAR bathymetry products generated to meet International Hydrographic Organization (IHO) standards to ensure gridded data positional accuracy in the horizontal (XY) and vertical (Z) frame. Arrangement of data Data has been processed and arranged into a GLOBE DTM grid using XYZ data. Spatial and temporal resolution of data within the dataset Image resolution is a 14m DTM grid. Length of time series Image created from data collected between 2019-07-17 and 2020-10-31 Amount of data expressed in number of stations, sites, observations, cores, months of recordings, miles of track or other units as appropriate Bathymetry image meets GLOBE DTM standard. Data provided under Creative Commons licence access and use conditions. Users of this data should provide the following attribution statement "Contains Irish Public Sector Data (INFOMAR, Geological Survey Ireland; Marine Institute) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence"

The Wexford Town Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), DateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m), and sea surface temperature (Celsius). The Wexford Town Tide gauge (52.3385, -6.4589) is owned and maintained by the Marine Institute and has been operational since April 2007. None

Irish National Tide Gauge Network (INTGN) 06: Kilrush Lough Tide Gauge, Co. Clare, Ireland 2016 - Present. Published by Marine Institute. Available under the license Creative Commons Attribution 4.0 (CC-BY-4.0).The Kilrush Lough Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), dateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). The Kilrush Lough Tide gauge (52.6319, -9.5021) is owned and maintained by the Marine Institute and has been operational since 2016. None...

The Kilrush Lough Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), dateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). The Kilrush Lough Tide gauge (52.6319, -9.5021) is owned and maintained by the Marine Institute and has been operational since 2016. None

The Howth Harbour Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), DateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). The Howth Harbour Tide gauge (53.3913, -6.0681) is owned and maintained by the Marine Institute and has been operational since October 2017. A tide gauge was previously installed in Howth Harbour from October 2006 but decommissioned in 2019. None

The Malin Head Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), dateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). The Malin Head Tide gauge (55.3717, -7.3344) is owned and maintained by the Marine Institute and has been operational since March 2008. None

LiDAR (Light Detection and Ranging) is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From satellite, aeroplane or helicopter, a LiDAR system sends a light pulse to the ground. This pulse hits the ground and returns back to a sensor on the system. The time is recorded to measure how long it takes for this light to return. Knowing this time measurement scientists are able to create topography maps.LiDAR data are collected as points (X,Y,Z (x & y coordinates) and z (height)). The data is then converted into gridded (GeoTIFF) data to create a Digital Terrain Model and Digital Surface Model of the earth. This LiDAR data was collected between June and October 2018.An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps. This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth’s surface.Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.This data shows the hillshade of the DTM.This data was collected by BlueSky and GeoAeroSpace and provided to the Geological Survey Ireland. All data formats are provided as GeoTIFF rasters but are at different resolutions. Data resolution is 1m.Both a DTM and DSM are raster data. Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. This data has a grid cell size of 1 meter by 1 meter. This means that each cell (pixel) represents an area of 1 meter squared.

The Aranmore Island Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), DateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m), sea surface temperature (celsius), and Pressure (measured variable) exerted by the atmosphere (MB). The Aranmore Island Tide Gauge (54.9905, -8.4955) is owned and maintained by the Marine Institute and has been operational since May 2008. None

Tide prediction provides data that predict the ebb and flow of sea tides and any irregular variations in their heights. Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth. The times and amplitude of tides at any given locale are influenced by the alignment of the Sun and Moon, by the pattern of tides in the deep ocean, by the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry. Tidal predictions have been generated from measured data via the Irish National Tide Gauge Network and via modelled data from the Marine Institute operational hydrodynamic model. Tidal prediction was a calculation of future tide ranges based on available oceanographic parameters. Users can select a station and date and time within the next 2 years for the tidal prediction using the menus available. Water Level was sea surface height above local Lowest Astronomical Tide measured in metres. Tide predictions cover the coastline of the Republic of Ireland. Tide predictions have been completed for a day period up to 2 years into the future. Tide predictions for any period in the past can be requested. Tide predications have been derived from harmonic analysis of data measured at the tide gauges around the Irish coast (Irish National Tide Gauge Network Real Time Data). There are also predictions for a limited set of locations based on data obtained from the Marine Institute Regional Ocean Modelling System (ROMS) model (Ocean Forecasts). The tide predications have calculated the water level due to tidal forcing for a particular period in time. Storm surge due to atmospheric pressure and wind effects is not accounted for in these predictions. Tide predictions have been provided to understand the ebb and flow of tides particularly to support warning in an extreme weather event coastal flooding risk. Tide predictions have been run by the Oceanographic Services team within Ocean Science and Information Services section of the Marine Institute (Ireland). Data completed for any time period.

LiDAR (Light Detection and Ranging) is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From satellite, aeroplane or helicopter, a LiDAR system sends a light pulse to the ground. This pulse hits the ground and returns back to a sensor on the system. The time is recorded to measure how long it takes for this light to return.Knowing this time measurement scientists are able to create topography maps.LiDAR data are collected as points (X,Y,Z (x & y coordinates) and z (height)). The data is then converted into gridded (GeoTIFF) data to create a Digital Terrain Model and Digital Surface Model of the earth. This LiDAR data was collected between May 2010 and May 2011. An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps. This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth’s surface.Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.This data shows the hillshade of the DTM.This data was collected by Transport Infrastructure Ireland. All data formats are provided as GeoTIFF rasters. Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. TII data has a grid cell size of 2 meter by 2 meter. This means that each cell (pixel) represents an area of 2 meter squared.

Irish National Tide Gauge Network (INTGN) 22: Dublin Port Tide Gauge, Co. Dublin, Ireland 2007 - Present. Published by Marine Institute. Available under the license Creative Commons Attribution 4.0 (CC-BY-4.0).The Dublin Port Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), DateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). The Dublin Port Tide gauge (53.3457, -6.2217) is owned and maintained by the Marine Institute and has been operational since February 2007. None...

The Roonagh Pier Tide gauge is part of the Irish National Tide Gauge Network which is a network of tide gauges located around the coast of Ireland collecting water level data as part of the development of a permanent tidal monitoring infrastructure. Parameters collected include; Station (ID), DateTime (yyyy-mm-ddThh:mm:ss), Water Level (Sea Level above Lowest Astronomical Tide [LAT], m) and Water Level (Water Level wrt Ordnance Datum Malin Head, m). The Roonagh Pier Tide gauge (53.7624, -9.9044) is owned and maintained by the Marine Institute and has been operational since 2016. None

LiDAR (Light Detection and Ranging) is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From satellite, aeroplane or helicopter, a LiDAR system sends a light pulse to the ground. This pulse hits the ground and returns back to a sensor on the system. The time is recorded to measure how long it takes for this light to return. Knowing this time measurement scientists are able to create topography maps.LiDAR data are collected as points (X,Y,Z (x & y coordinates) and z (height)). The data is then converted into gridded (GeoTIFF) data to create a Digital Terrain Model and Digital Surface Model of the earth. This LiDAR data was collected in 2011.An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps. This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth’s surface.Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.This data shows the hillshade of the DSM.This data was collected by the Office of Public Works. All data formats are provided as GeoTIFF rasters. Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. OPW data has a grid cell size of 2 meter by 2 meter. This means that each cell (pixel) represents an area of 2 meter squared.

The tide tables cover the world in four volumes, re-published annually. Volume 1 covers United Kingdom and Ireland (including European Channel Ports) Volume 2 covers Europe (excluding United Kingdom and Ireland), the Mediterranean Sea and Atlantic Ocean.
Volume 3 covers the Indian Ocean and South China Sea.
Volume 4 covers the Pacific Ocean and adjacent seas.

Each volume has an introductory section briefly describing methods of prediction and the effect of meteorological conditions on tides, and comments on special tidal problems of the area covered.

The main function of the tables is to give daily predictions of the times and heights of high and low waters at about 240 Standard Ports, and further information in the form of time and height difference from the standard ports for about 6500 Secondary Ports. The tables also give the four main harmonic constants for about 5000 ports, both Standard and Secondary. In addition, where necessary, information is provided which enables shallow water corrections to be applied. The tables include instructions and worked examples.

Supplementary information provided consists of tables which give methods of obtaining intermediate heights between high and low water; special data for the double-tide area around the Isle of Wight; conversion tables from feet to metres; tables of tidal levels at standard ports; the connections between Admiralty Chart Datum and Land Survey Datum in the British Isles and in some other ports; tables of tidal angles and factors; astronomical arguments for use in the harmonic prediction and analysis of tides. Volumes 3 and 4 also contain daily predictions for tidal streams in certain areas where the streams are of particular navigational importance and where predictions in this form are possible. Tidal stream harmonic constants are also included for a few positions in Volumes 2, 3 and 4.

In addition, times and heights of high and low water, hourly and ten minute heights can be produced by the Hydrographic Office on disc or as an e-mail attachment through the Tidal Prediction Service.

Also available is a disc enabling tidal prediction by the Simplified Harmonic Method for Windows (DP560).