Oil from the leaking Deep Horizon oil rig is seen swirling through the currents in the Gulf of Mexico Thursday, May 6, 2010. BP will attempt to drop a containment dome on the main leak this week in an effort to staunch the flow of crude oil. (AP Photo / Dave Martin)

By HARRY R. WEBER and TAMARA LUSH (AP) ON THE GULF OF MEXICO — The captain of a boat hauling a box that is designed to capture the oil spewing into the Gulf says the delay in lowering it into the ocean is being caused by oil fumes that could ignite. Capt. Demi Shaffer tells The Associated Press Thursday night that the crews do not want to be fighting a fire while trying to unload the giant concrete-and-steel box over the blown-out oil well at the bottom of the sea. The AP is the only news organization on board the vessel 50 miles off the coast of Louisiana. Shaffer says because of the lack of wind to circulate the air, the fumes from the thick oil surrounding the boat were rising to a level that any spark could start a fire. That includes metal on metal. Crew members are wearing respirators. It was unclear when they would be able to proceed.

AP: Oil fumes delaying lowering containment box