Coast Guard investigating subs

NEW ORLEANS (AP) - The U.S. Coast Guard says there is some sort of substance on the water in the Gulf of Mexico, and officials are collecting samples to determine what it is.

Coast Guard spokeswoman Casey Ranel says the agency is sending out a cutter Sunday morning to collect samples of the substance, which was spotted off the coast of Louisiana. She says an airplane also is expected to fly over so officials can get a better idea of what's in the water.

A press release sent Saturday night said the Coast Guard was investigating reports of an oil sheen in the Gulf. The Coast Guard says there is a substance in the water, though officials have yet to determine what it is.