Notice to Mariners: Mare Island Causeway Bridge Work Due to Commence in December

The Mare Island Causeway Bridge (mile 2.8) is scheduled for major work from December 2025 through late 2026. The work will affect vessels trying to navigate up or down the Napa River, though concessions are being granted to accommodate a couple of events.

Carl Hausner, chief, Bridge Section of the USCG Southwest District, outlined the dates and times that the bridge lift span will be secured in the closed-to-navigation position.

The lift span of the bridge will be secured in the closed-to-navigation position Mondays through Thursdays, 7 a.m. to 5 p.m., and Fridays, 7 a.m. to 11 a.m. and 12 noon to 5 p.m., Dec. 22, 2025, through late March 2026. The bridge will resume normal operations outside these time frames.

The lift span of the bridge will be secured in the closed-to-navigation position Mondays through Fridays, 5 a.m. to 1 p.m., and 2 p.m. to 3 p.m., late March through June 30, 2026. The bridge will resume normal operations outside these time frames.

The lift span of the bridge will resume normal operations for the following events:

Bottle Rock: May 22, 23 and 24, 2026.

Sausalito Yacht Club 7th Annual Cruise to Napa Valley Yacht Club: May 28, 29, 30 and 31, 2026.

Temporary underdeck platforms will be installed below the lift span bridge deck, reducing the vertical clearance in the open and closed positions by four feet. In the event of an emergency, the lift span can open with two hours’ advance notice given to the bridge operator.

There was no schedule that could be made to take into account all mariners’ concerns. It would greatly extend the time frame for the project and cause more delays and economic impacts for all, including the City of Vallejo.

If you wish to comment on this revised schedule, please do so by close of business, Sept. 30, 2025. Comment will be received at [email protected].

Thank you to Kirby Long of Napa Valley Marina for forwarding the information. Kirby also created the easy-to-read schedule below. We suggest you save it for easy reference.