If you ask mariners, they’ll tell you, navigating a boat from the open ocean into the San Francisco Bay is notoriously treacherous. There’s the dense fog that can make it hard to see. Strong currents constantly rearrange the sea floor and can quickly throw a vessel off course. And finally – our bridges! If a boat were to strike a pillar it could be catastrophic. That’s why captains of big ships aren’t allowed to navigate into port on their own. A specially trained mariner called a bar pilot – hops aboard every ship that comes into San Francisco Bay, and takes over command. Bay Curious listener Erik Udd wants to know everything about how it all works.Additional Resources: Why Specialized Mariners Are Required on Every Ship Sailing Into San Francisco Bay Read the transcript for this episode Sign up for our newsletter Got a question you want answered? Ask!Your support makes KQED podcasts possible. You can show your love by going to https://kqed.org/donate/podcastsThis story was reported by Katrina Schwartz. Bay Curious is made by Christopher Beale, Olivia Allen-Price and Katrina Schwartz. Additional support from Jen Chien, Katie Sprenger, Maha Sanad, Ethan Toven-Lindsey and everyone on Team KQED.Learn more about your ad choices. Visit megaphone.fm/adchoices