On Wednesday, February 4, 1970, amidst heavy rain and winds from the southeast reportedly gusting up to 60 knots, the Liberian tanker ARROW ran aground on Cerberus Rock in Chedabucto Bay, Nova Scotia. She was under charter to Imperial Oil Limited and had been en route to Nova Scotia Pulp Limited with a cargo of 108,000 barrels of Bunker C fuel.

On grounding, the forward half of the ARROW suffered extensive damage, and oil began to flow from the ruptured tanks. Over the next 14 hours, much of this oil was transported to the shores north of Cerberus Rock by the prevailing winds and currents. As the storm moderated and the wind shifted, oil slicks, some miles in extent, were driven toward the south coast of the Bay. Some of the oil may have escaped from the Bay. On February 8, the ARROW broke in half at her No. 5 tank, the contents of which were thus spilled into the sea. Two days later the wind shifted from the northwest to the southeast and this oil in turn was driven toward the north shores of Chedabucto Bay. On February 12, the stern section sank in 90 feet of water carrying with it a good third of the cargo. The tanks containing this oil remained essentially intact, and very little oil was to escape from the stern section after it had settled to the sea bed.

Gale force winds from the east and later from the southwest moved more oil into the Inhabitants Bay, Janvrin Island, and Isle Madame areas. In the days following, oil moved toward the open sea.

By the eighth day, February 12, an estimated one half of the ship's cargo of oil had been released and the calamity had reached catastrophic proportions. Out of the 375 statute miles of shoreline in the Bay area, 190 miles had been contaminated in varying degrees.

Oil continued to issue from the forward section of the wreck, and there remained the threat of a further massive flow of oil should the after section break up before its contents could be recovered. Oil afloat in the Bay and at sea threatened fishing operations, fish-packing plants, the as-yet unpolluted shores, bird life and the marine ecosystem.

Air temperatures were generally in the range of -10 to 0 degrees C. Gale force winds, snow, freezing rain, and rain could frequently be expected. Sea water temperatures were close to the freezing point and sea ice was building up in the sheltered bays and passages. The behavior of the heavy Bunker C oil in this frigid environment was recognized from the beginning as a key problem in the clean up operation and a central point for scientific investigations.

[exerpt from Report of the Task Force - Operation Oil (Clean-up of the Arrow oil spill in Chedabucto Bay) to the Minister of Transport, Volume II]