As soon as we rounded R10 to cross the channel and could see south towards San Pedro, we saw a huge fog bank. NOAA satellite imagery showed it blanketing Orange County and not above LA, however as we looked away and back at the fog we could tell it was getting closer, and fast. A few minutes later and we were surrounded. The weather changed from hot, calm and sunny, to cold, gusty and misty fog, visibility was around 100 feet. I kept my eyes on the compass to keep us steered toward Catalina and blew the handheld fog horn every few minutes. Mia kept her eyes open for any craft behind us or to our port, I looked for anything in front of us and starboard. She periodically looked at our Marine Traffic app for clues to other boats whereabouts if they had AIS, oh yeah and container ships. My dad used to say that the trip to Catalina is a piece of cake except for one thing - fog banks in the channel. We saw one powerboat, he was heading right at us, we saw each other and each corrected course and passed each other within 60 feet. Who knows if we came close to other boats out there. This lasted for about an hour and a half and we reached a pocket of lighter fog and wind, then eventually it parted and we could see our target again.