Arrived at Ayamonte on 09/07/2010, after motoring (no wind) down from Faro. The wind did get up in the afternoon, but our time of arrival was dictated by the need to enter the Rio Guadiana at slack water. It can run at 6 knots or more during springs. The river forms part of the Portugal/Spain boundary, so it was felt a good place the switch our courtesy flag to that of Spain. The plan is now to explore upriver. Possible for some twenty miles or so.