The Amoco Cadiz and coast of Brittany.
The Amoco Cadiz contained 1,604,500 barrels (219,797 tons) of Arabian Light and Iranian Light crude oil.[ Both are medium
weight oils with an API gravity of 34.8. Bunker C is a heavy product with an API of between 7 and 14. But severe weather result-
ed in the complete breakup of the ship before any oil could be pumped out of the wreck. Therefore its entire cargo of crude oil
(cargo which belonged to Shell) spilled into the sea.
A 12-mile (19 km) long slick and heavy pools of oil were smeared onto 45 miles (72 km) of the French shoreline by north-
westerly winds. Prevailing westerly winds during the following month spread the oil approximately 100 miles (160 km) east
along the coast. One week after the accident, oil had reached Côtes d'Armor.
Oil penetrated the sand on several beaches to a depth of 20 inches (510 mm). Sub-surface oil separated into two or three lay-
ers due to the extensive sand transfer that occurred on the beaches during rough weather. Piers and slips in the small harbors
from Porspoder to Brehat Island were covered with oil. Other affected areas included the pink granite rock beaches of Tregastel
and Perros-Guirrec, as well as the tourist beaches at Plougasnou. The total extent of oiling one month after the spill in-
cluded approximately 200 miles (320 km) of coastline. Beaches of 76 different Breton communities were oiled.
Oil persisted for only a few weeks along the exposed rocky shores that experienced moderate to high wave action. In the
areas sheltered from wave action, however, the oil persisted in the form of an asphalt crust for several years.