Rio Urionsea kayak wave surfing video (in Tigre suburb of B.A.) this is a distributary of the Rio Parana in Buenos Aires which joins the Rio San Antonio.
Kite Beach (aka Peru Beach) clearly can have wind because kiters play there. Would it be good for laps? This beach is not far from river estuaries.
Rada Tilly coastal kite surfing spot. Downwinding? Not great for inexperienced paddlers because the average wind direction is from the west - offshore. The coastline is curved to the NE north of town so some days with SW might work for downwinders to the north.
Villa La Angostura - another kiting site - potential for downwinding? Fairly remote, probably quite cold water.