Arctic drill ships leave Seattle for Alaska

Two vessels fitted with drilling rigs left Seattle Wednesday for Alaska.

The Kulluk and Noble Discoverer and support ships are headed first to Dutch Harbor. Once open water allows, the rigs will move to the Beaufort and Chukchi seas for offshore drilling.

Shell Oil prepared the ships in Seattle to explore for oil and natural gas. New oil discoveries could feed the trans-Alaska pipeline.

Coast Guard vessels escorted the blue and white vessels through Seattle's Elliott Bay, maintaining a 500-yard safety zone.

Environmental groups, including Greenpeace, oppose the drilling because they fear an oil spill in ice-choked ocean waters.