Home | Links | ©| Contact Us

Cork Harbour and Coast (Youghal to Kinsale)
Cuan Chorcaí agus Cósta (Eochaill go Cionn tSáile)


The natural harbour of Cork Harbour is located on the south coast of Ireland, inside the headlands of Roches Point to the east and Weaver’s Point to the west. The distance across this narrow mouth is just less than 1.5 kilometres.

Within the bay, there are a number of islands including Great Island, Spike Island, Rocky Island, Hawlbowline Island, Corkbeg Island, Little Island, Weir Island, Foaty Island, Brown Island, Brick Island, Harper’s Island and Hop Island.

A number of rivers enter the harbour, most notably the River Lee at Cork City in the upper reaches but also the River Owenabue at Crosshaven, the River Minane at Ringabella on the westend shores of the harbour and the River Ballynacorra at Ballynacorra to the east.

Cork Harbour, with others, is claimed to be the second largest deep water port in the world behind Sydney, Australia.

The name "Youghal" derives from the old Irish "Eochaill" - meaning "Yew wood". Youghal is situated in the South East of Cork and borders County Waterford. It is a seaside resort town and sits on the estuary of the River Blackwater.

Kinsale Harbour is situated south of Cork City. The harbour area can be defined by Shroneean Point to the west and Preghane Point to the east. The Port of Kinsale Harbour authorities have placed an aid to navigation buoy called the Bulman Buoy just to the north west of this headland. The distance across the harbour mouth is just under 1 kilometre.

Further inside the harbour the remains of two military forts, Charles Fort on the east and James Fort to the west, dating from the 17 th century dominate the approaches to the inner harbour. The distinctive Old Head of Kinsale headland provides shelter in its lee for the area just seaward of the mouth of the harbour.

The River Bandon enters the sea at Kinsale where the sheltered harbour has led to its development as an important commercial and recreational port.

Location of Cork Harbour, Youghal and Kinsale in Co. Cork on the south coast of Ireland.

Back to Top

INFOMAR Survey History

INFOMAR surveys of Cork Harbour and Approaches began in 2005 when the Celtic Voyager was used to map an area just seaward of the harbour mouth and along the shipping channel up to the Port of Cork. In 2007, the surveyed area around the mouth of the harbour was extended, again with the voyager as the survey vessel.

The Celtic Voyager mapped a large portion of the seabed off the Cork coast from the Old Head to Ballycotton in 2008 that included a large portion of the approaches to Cork Harbour. Further surveys were carried out by the Celtic Voyager in 2010, 2012 & 2013.

In 2010 the RV Keary surveyed around Kinsale. The RV Geo, RV Keary and Cosantóir Bradán surveyed the harbour in 2012.

The RV Geo, RV Keary and RV Tonn surveyed the Youghal\Dungarvan area in 2015.

Further surveys offshore were carried out by the Celtic Voyager in 2016.

Coverage from survey legs undertaken to survey Cork Harbour to date. (Click image for more detailed map)

Survey Coverage polygons can be downloaded as a shapefile from our Interactive Web Data Delivery System (IWDDS).

Select your area of interest. Vector datasets - Offshore - Offshore Shapefiles


Read more about some of the survey legs on our Blog by clicking on the links below.

KRY10_02 Kinsale Harbour and Approaches

CV10_03 Cork and Waterford

CV10_02 Wexford Waterford and Cork

CV 13 01 South Priority Area

Back to Top

Bathymetry (Water Depth)

Water depth varies from 0 to 95 m.

Detailed .pdf charts of the bathymetry of Cork can be downloaded by clicking here

You can download Bathymetry xyz data from IWDDS.

(Data Type: Vector Datasets, Region: Offshore, Theme: Bathymetry (Survey Leg) entire survey leg or Bathymetry (Survey Line) for individual tracklines. Take note of the survey names in INFOMAR Survey History.

You can also download the bathymetry data in ArcGIS GRID format


Back to Top

Shaded Relief

The 3D appearance is achieved using software called Fledermaus. By using some vertical exaggeration, artificial sun-shading (usually as if there is a light source in the nw 315°) and colouring the depths using various colour maps, it is possible to highlight the subtle relief of the seabed. This helps us to quickly understand the variation in depths.

MBES shaded relief image of the seabed seaward of the mouth of Cork Harbour showing a meandering channel feature between rock outcrops.(Click image for more detailed map)

MBES shaded relief image of a pipeline partially covered by sediment running offshore off the coast of Cork. (Click image for more detailed map)

Detailed MBES shaded relief image of an area of rock outcrop off the Cork coast at Robert’s Head, west of the mouth of Cork Harbour. This image clearly illustrates that submarine rock outcrops follow a similar strike direction of ENE to WSW, as seen in onland outcrops of sedimentary rocks which are predominantly composed of sedimentary rocks, mainly sandstones, siltstones and mudstones which are Devonian (410 to 354 million years ago) and Carboniferous (354 to 298 million years ago) in age. Also visible are areas where folding and distortion of the rock layers has occurred when horizontal layers of sedimentary rocks are exposed to tectonic forces during events such as mountain building events, namely the Variscan Orogeny and to a lesser extent the Alpine Orogeny. (Click image for more detailed map)

Multibeam sonar data collected west of Big Sovereign island, east of Kinsale Harbour, showing well exposed, folded and faulted bedrock on the seabed.

The most prominent features are a series of northwest to southeast and north to south trending channels which are coloured in purple in the image above.

All of our Charts for Cork can be downloaded in pdf format from this page.

Download Shaded Relief Bathymetry Geotiffs from our Interactive Web Data Delivery System (IWDDS)

Select your area of interest.Offshore Geotiffs - Bathymetry Shaded Relief Geotiffs.

Back to Top


Multibeam Systems also collect additional information, including the strength of the acoustic signal (or return) from the seafloor. This is known as Backscatter. Differing seafloor types, such as mud, sand, gravel and rock will have different Backscatter values depending on the amount of energy they return to the sonar head. Rocky areas will typically have high returns while soft sediments like mud are more likely to absorb energy and have low Backscatter returns. These differing values are used to generate a grey-order image (i.e. dark for high returns, bright for low returns) of the seabed which can be used to examine the nature of the seafloor.


The image above is a section of interpreted backscatter mosaic from an area south of the mouth of Cork Harbour. Dark areas with rough texture represent areas of outcropping bedrock. Dark areas with smooth texture probably represent coarse sand and gravel and light areas with smooth texture are probably sand.

The image above is an interpreted section of backscatter mosaic over an area which includes a large scale channel and its flanks. The seabed along the channel is characterised by light backscatter areas and is interpreted as fine sands and silts. Light backscatter returns are more widespread in the southern part of the channel. Soft sediment is probably being transported seaward along the channel and deposited where the gradient decreases. Outcropping bedrock is evident at the western side of the channel. Subcropping bedrock with a thin veneer of sediment is the dominant seabed type to the east of the channel. Some outcropping bedrock is also found in this area.

Detailed .pdf backscatter charts can be downloaded by clicking here

Download Backscatter Geotiffs from our Interactive Web Data Delivery System (IWDDS)

Select your area of interest.Offshore Geotiffs - Backscatter Geotiffs.

Back to Top

Ground Truthing/Seabed Sampling

To verify the results of remotely sensed sonar data, it is important to collect physical sediment samples from the seabed. These may be from the surface where grabs are used or may penetrate through the seabed and retain the vertical structure of the sediment by using various coring methods. These samples are also critical for the confirming seabed classifications.

Approximately 90 seabed samples have been taken in the area. Theses were collected in 2008, 2012 & 2013 by the Celtic Voyager. These were taken using a day grab sampler in 2008 and a shipek grabin 2012 & 2013.


The recovered samples are sent to a laboratory for particle size analysis and the results are used in the creation of seabed classification charts incorporating both MBES and groundtruth data.

Very Coarse shelly sand collected south east of Roberts Head

Sample locations can be downloaded as a shapefile from our Interactive Web Data Delivery System (IWDDS).

On the IWDDS Select your area of interest. Vector datasets - Offshore - Offshore Shapefiles

Back to Top

Seabed Classification

Seabed classification is an advanced process in which a backscatter image is interrogated using special software in order to divide it into areas which have similar characteristics. Areas which have a similar nature are grouped together and divided into separate classes. These classes are colour coded and developed into seabed classification charts.  

The classification of the multibeam dataset from the Cork coast resulted in the creation of a 4 class classification.

Seabed Classification Chart for Cork(Click on image for more detailed map)

Further information about the classification process can be found in the Data Processing section.

For a more detailed .pdf chart of the seabed classification of Cork click here

You can download the Seabed Classification in ArcGIS GRID format data from IWDDS

(Data Type: ArcGIS GRIDS, Region: Offshore ArcGIS, Theme: Seabed Classification ArcGIS GRID

Back to Top


Youghal Geology

The coastline around Youghal is composed of a mixture of limestones, shales and a famous rock formation known as the Old Red Sandstone (represented as light brown on the map here). The seabed data shows clear areas of rock outcrop, cut through in places by strips of smooth seabed. Perhaps the wide strip running south-southeast in the centre of the seabed data is an ancient extension of the estuary in Youghal, formed when the sea-level was lower.

Cork Harbour Geology

The geology of Cork Harbour is dominated by limestone and sandstone, with some occurrences of mudstone. Note in the image the broadly east-northeast to west-southwest trending ribbons of the different rock types. The basic shape of Cork Harbour seems to follow the trend of the limestone and may be because this rock is relatively easy to weather and erode – perhaps the rivers and the sea preferntially eroded these rocks instead of the sandstones. Limestone is a carbonate rock that formed many millions of years ago in warm, shallow seas. The largest sandstone formation here is called the Old Red Sandstone and dates back to the Devonian period.

Kinsale Geology

The rocks surrounding Kinsale harbour are mostly sandstones and mudstones that were laid down as sediments hundreds of millions of years ago during the Carboniferous period. The shape of the harbour itself seems to extend offshore as a gap in the bedrock in the seabed data – perhaps this was the original extent of the harbour during a time of lower sea level. The inlet to the east, near Oysterhaven, seems to follow the same trend of having an underwater expression in the seafloor bedrock.

Onshore Bedrock Geology shapefiles can be downloaded from our Interactive Web Data Delivery System (IWDDS).

On the IWDDS Select your area of interest. Vector datasets - Onshore - Bedrock

Offshore Geology shapefiles can be downloaded from our Interactive Web Data Delivery System (IWDDS).

On the IWDDS Select your area of interest. Vector datasets - Offshore - Offshore Shapefiles

Back to Top



To view the shipwrecks in Google and to download Shipwreck Information Sheets please click here

Shipwreck locations can be downloaded as a shapefile from our Interactive Web Data Delivery System (IWDDS).

On the IWDDS Select your area of interest. Vector datasets - Offshore - Offshore Shapefiles

Back to Top


INFOMAR in Google Earth

Download the bathy lidar Clonakilty to Midleton 10m dataset.

Download the bathy lidar Midleton to Youghal 10m dataset.

To view additional datasets in Google Earth please click here

Back to Top

View data in the free iView4D

Download the free viewer here

Download the Clonakilty to Midleton 10m dataset here

Download the Midleton to Youghal 10m dataset here

To view additional datasets in Google Earth please click here

Back to Top

Data Access

Full details outlining the process to gain access to datasets for the bay above or all INFOMAR data can be found in the INFOMAR | Data page of this website.

Back to Top

Return to Survey Details Map

Follow these links to your area of interest on the INFOMAR website:

About | Surveying | Data & Products | News & Updates | Press Releases | Publications | Associated Projects | Image Gallery | Contact Us | Home

Find Us
Geological Survey of Ireland Geological Survey, Ireland
Beggars Bush, Haddington Road
Dublin 4
Marine Institute Marine Institute Headquarters,
Rinville, Oranmore
Co. Galway
The National Development Plan
a modus site