Riou positioned himself near the iceberg, and despatched boats to collect the ice. By the time the last boats had been recovered night had fallen, when a sudden fogbank descended, hiding the iceberg from view. Riou found himself in a dangerous situation. Somewhere to leeward lay a large mass of ice, concealed in the darkness and fog. He posted lookouts in the bows and rigging, and began to edge slowly forward. After sometime the danger seemed to be past, and the iceberg left behind, when at 9 o'clock a strange pale glow was reported by the lookout in the bows. Riou ordered the helm to turn hard a starboard, turning into the wind as a wall of ice higher than the ship's masts slid by along the side. It briefly appeared that the danger had been avoided, but as she passed by, "Guardian" struck an underwater projection with a sudden crash. Caught in a sudden gust of wind the ship reared up and swung about, driving the stern into the ice, smashing away the rudder, shattering her stern frame and tearing a large gash in the hull. Despite the seriousness of the situation Riou remained calm, using the sails to pull clear of the ice, and then taking stock of the damage.