PRECAUTIONARY AREA
Traffic lanes and the associated precautionary area established at the approaches to San Francisco Bay are completely shown on ENC US4CA11M. Traffic within the Precautionary Area may consist of vessels making the transition between the Main Ship Channel and one of the established traffic lanes. Mariners are advised to exercise extreme caution when navigating within this area. When passing Traffic Lane Lighted Buoys "S", "W", or "N", inbound vessels should contact the pilot boat on Channel 13 for boarding instructions.