QUESTION: What ever happened to the Hawaii-based Coast Guard vessel that was sent to the Gulf of Mexico to help with cleanup efforts?

ANSWER: The Coast Guard cutter Walnut has taken a break from its four-month-long deployment in the gulf for a routine change-in-command ceremony in Pensacola, Fla., to relieve its commanding officer.

According to the Deepwater Horizon Joint Information Center in New Orleans, the personnel change — a regular rotation scheduled every year or two — is not expected to alter the cutter’s mandate in the gulf.

"Their primary operation is skimming oil at the source," said Petty Officer 3rd Class Matthew Masaschi in a phone interview from New Orleans. "They’ll go back to resuming skimming oil operations."

Masaschi said the cutter — one of 20 Coast Guard vessels working in the disaster zone — has been collecting oil immediately above the blown BP well since it arrived in June.

The Walnut is one of 16 cutters in the U.S. fleet outfitted with oil-skimming equipment. Crews corral the viscous oil using buoys, then suck the hazardous material out of the water using a specialized vacuum tube.

The 225-foot buoy tender is also equipped with advance satellite and radio systems that have allowed it to coordinate recovery efforts with government vessels and private contractors.

The Deepwater Horizon rig exploded April 20, claiming 11 lives and spewing hundreds of millions of gallons of oil into the gulf. BP said it capped the gushing well on July 15 but is still running tests to determine whether the cap has led to seepage elsewhere on the sea floor.

The Walnut’s deployment to the region is expected to end in September. It is not clear how the newly installed cap will affect the cutter’s operations.