Some links of interest:

Angling ChartsAngling charts for Lough Corrib and other fishing lakes
Athlone IWAIAthlone IWAI
Athlone Sub-AquaAthlone Sub Aqua Club
Barge HawthornThe Hawthorn Blog, Irish travels, sketches and recipes
Carrick-on-Shannon IWAICarrick-on-Shannon Branch – IWAI
Clonmacnoise BridgeArchaeological excavations of medieval bridge
Down SurveyDown Survey of Ireland 1656 to 1658 – first detailed land survey in the world
Dublin IWAIDublin IWAI
IWAIInland Waterways Association of Ireland
Irish Waterways HistoryForgotten navigations, scenery, boats, waterways operations, past & present
Kildare IWAIKildare IWAI
Lough Derg IWAILough Derg IWAI
NMS – underwater archaeologyNational Monuments Service – underwater archaeology unit
Offaly IWAIOffaly IWAI
Ordnance Survey IrelandOrdnance Survey Ireland , reference material on positioning ITM etc
ReelaxingSurveying on Lough Ree and throwing the odd line out
Underwater IrelandPhotos and videos of Irish rivers and lakes, just below the surface
UU – maritime archaeologyUniversity of Ulster – maritime archaeology unit
Memory Map UKMemory Map software
Open CPNChartplotter and GPS Navigation Software