CERGY (95) 16.08.2014

On 16 August 2014 at 21:55, a witness in a boat on the Oise saw a black rectangular object with rounded corners for 10–20 seconds before trees hid it. It moved silently and horizontally in a straight line from Cergy toward Pontoise, west to east. Night was beginning; sunset had been at 21:03. Météociel recorded a light westerly wind of 6–18 km/h. GEIPAN considered a child's helium-filled balloon carried by the wind. Such balloons have varied shapes and can look rectangular from some angles. It could not confirm the hypothesis, but the date, described in the source as the end of a summer weekend, fits a festive release. GEIPAN classifies the case B: probable party balloon.