The area - the mouth of the river Ebre/Ebro is flat and sandy. We sailed from Vilanova i la Geltru, which we liked, to anchor off Sant Carles (round the corner from the harbour) and then to Peniscola, which we weren't so keen on (although we also anchored by the harbour there, which was fine). When we were there - July - the weather was hot and rounding the Ebre delta it was flat calm. There seemed to be no anchoring restrictions and we could see a number of yachts moored in the large bay/lagoon east of Sant Carles. I don't know about the north side of the delta. Depths are shallow as I recall (just look on Google map . . . ) and I guess seas will kick up quickly when there's a blow. Looking back, could be nice quiet cruising ground, but might get a bit boring after a while. But Barcelona's within easy reach - for culture, excitement (and muggings!).