Hi Richard.
If you wish to go to New Ross, go on a rising tide and you'll be there in a couple of hours, marina on the right as you approach the road bridge, can't miss it. Supermarkets Aldi & Lidl close to the marina for resupply.
The marina is no more expensive than Waterford and if you don't like it you can always go back.
If you ask around the marina for John Dimond, he'll get you a guide/chart for the Barrow,Suir & Nore known locally as 'The 3 Sisters' rivers.
For information on the rest of the Irish Inland Waterways contact info@waterwaysireland .com and they'll post you some free guides.
The route we took was from Kilmore Quay, Milford haven, Padstow(very nice), Falmouth, Plymouth, Brixham, Weymouth, Poole, Lymington, Southampton(for the Boat show),Portsmouth,Brighton, Eastbourne,Dover, Dunkirk.
Our cruising speed is 7 knots and we used the tides to help push us along.
The longest days cruise was 12 hours from Padstow(outgoing tide to Lands End, then incoming tide) to Falmouth
The rest of the days cruises along the coast were from just a few hours up to 1 tide (6/7 hours), we checked the local tourist office's before we arrived at the marina's for the local attractions/hostelries. We always moored at the town quays where possible as they were cheaper than the large marina's.
We highly recommend treating it as a leisurely summer cruise rather than a charge along the coast and miss so many interesting things..
We will follow the same route this summer as it is a most enjoyable journey.