kellerman's workday starts at pier nine in san francisco where he boards a small boat that will take him to the port of oakland. there he'll climb on to a container ship and guide it out to the open sea. both state and federal law require a local pilot to take over from the ship's captain then steer the ship in and out of the bay, not just to protect the cargo but the bay itself. >> when we first started back in 1850, we were brought on to keep the ships safe from the environment. now we're keeping the environment safe from the ships. >> reporter: today keller man is boarding a state-of-the-art cargo ship delivering anywhere from $150 to $300 million worth of goods to hawaii. they serve as the human link in the supply chain, responsible for almost all containerized goods moving through northern california. as we pull up next to the ship, we get one final instruction -- >> no swimming. >> no swimming. >> that's right. >> reporter: it's a steep climb, no safety net or harness. luckily it's a beautiful day, but this is the bay area after all and conditions can deteriorate rapidly. >> he