A ship carrying some of the largest cranes in the country anchored in the sheltered waters of Drakes Bay for the past week before making the final leg of its journey to the Port of Oakland on Wednesday morning. The boat, the Zhen Hua 35, is carrying three 400-foot cranes from Shanghai that are specialized for moving shipping containers. Choppy waters have spoiled a few target dates, but the weather was calm enough this week. The cranes’ booms were lowered to pass under the Golden Gate and Bay Bridges, and a San Francisco mariner with experience in challenging waterways boarded the ship to direct its navigation to a channel near Yerba Buena Island, where the booms will be raised again so the cranes can be rolled onto the terminal. Tugboats will berth the ship, then crews will take another couple of weeks to remove three old cranes and set up the new ones before using them to place all types of cargo on ships crossing the Pacific Ocean. The cranes—the largest ever seen at the Port of Oakland—were invested in by Stevedoring Services of America for $30 million. They can lift containers 174 feet above the dock and reach 225 feet across a ship’s deck. “Those boxes have everything you and I count on,” port spokeswoman Marilyn Sandifur said. “The food that’s grown on the farms near you ends up being handled by the cranes you’re seeing out on Drakes Bay.” The boat, which flies under the flag of Libera, has attracted interest from nautical enthusiasts and visitors to the Point Reyes National Seashore.