I’ve put up some photos of this short river navigation, one of the earliest to be tackled in Ireland. It may still be navigable, certainly by small boats and perhaps by something larger. I understand however that the entrance from the Shannon Estuary is tricky and requires local knowledge.
There is a bit of a mystery about the quay in Adare. A stretch of canal has disappeared and the bridge at Ferrybridge has lost its opening arch. But there are still things to see ….