English: This high-resolution image shows Petit Bois Island (top right) and the eastern end of Horn Island (top left) on June 26 2010. In general, oil-covered waters are silvery and cleaner waters are blue-gray. This pattern is especially consistent farther from the islands. The intensely bright patches of water directly offshore of the barrier islands, however, may be from a combination of factors, including sediment and organic material, coastal currents and surf, and oil.

The islands provide a sense of scale for the ribbons of oil swirling into the area from the south. Petit Bois Island is about 10 kilometres long.

Although oil has been observed in the Sound, it is unlikely that all the bright patches of water in that area are thickly oil-covered. Differences in brightness in coastal area waters may be due to other factors, including freshwater runoff, strong currents, and water depth and clarity.