2011:456 - BLIND HARBOUR, BEALNAGUNNAMORA, POLLNACAPPUL, Mayo

In 2007 the Underwater Archaeology Unit (UAU) of the National Monuments Service received a report regarding the discovery of two previously unrecorded cannon on the seabed in Broadhaven Bay, Co. Mayo. A two-day dive and metal-detection survey carried out by the UAU in August 2009 identified six iron cannon at the site. The UAU returned to the site in 2010 and 2011 to carry out further survey work to map the known extent of the wreck site. A small-scale rescue excavation was also carried out in 2011 to try and ascertain the date and identity of the wreck and to retrieve artefacts in danger of being lost or washed away. The site is located at the north-eastern end of the Mullet Peninsula on the western side of Broadhaven Bay at the entrance to Blind Harbour in approximately 4–8m of water.
To date, the underwater survey and excavation have resulted in the discovery of twelve iron cannon, a spread of concreted cannon-balls, eight boat-shaped lead ingots, pewter bottle tops, bricks, two wooden barrels and a number of smaller artefacts. No structural remains of the ship have been discovered thus far. A detailed survey was undertaken of the cannon in an attempt to record their form and calibre and to establish whether any distinguishing marks or diagnostic features were present. The cannon lie scattered and dispersed apparently haphazardly over a 40m stretch of the seabed. Their layout indicates that they were not deposited on the seabed as part of a coherent ship structure but implies that the ship met with quite a violent end, resulting in its total break-up against the cliffs during the wrecking process. The wreck has a mixture of cannon that vary in type, size and calibre. All of the twelve cannon recorded are iron and it appears that there are two types, comprising eleven cast-iron muzzle-loaders and a cast-iron breech-loading gun. All of the cannon are heavily concreted, which makes it difficult to examine them in any detail, leaving their analysis open to interpretation. Initial analysis indicates, however, that the wreck is likely to be of mid-17th-century date.
Eight boat-shaped lead ingots also found during the course of the survey were subsequently recorded, lifted and brought to the National Museum of Ireland. The ingots were found in four loose groups spread out over a 200m area of seabed. The style and stamp marks on the lead ingots find close parallels among ingots discovered on 17th-century Dutch East Indiaman wrecks from Britain, Australia and further afield and would also appear to support a mid-17th-century date range for the wreck site.
The presence of the ingots, the pewter bottle tops and other artefactual evidence all point towards the wreck being that of a mid-17th-century Dutch East Indiaman. The discovery of such a wreck in our waters is a unique find and there is a strong possibility that the records of the Dutch East India Company may contain the entire story of the ship and its loss. Further research and investigation are planned for 2012 to determine further the nature, extent and, if possible, the true identity of this wreck, and to assist in the formulation of a definitive long-term management strategy for the site.

Underwater Archaeology Unit, National Monuments Service, Department of Arts, Heritage and the Gaeltacht, Custom House, Custom House Quay, Dublin 1