San Francisco Bay Ferry, San Francisco, celebrated the commissioning of the high-speed ferry Zalophus, the 19th vessel in the SF Bay Ferry fleet. Zalophus follows Karl, which entered service in spring 2025. The vessels were the nation’s cleanest high-speed, high-capacity passenger ferries and are powered by four U.S. Tier 4 engines equipped with diesel particulate filters (DPF).
“Adding MV Zalophus to the San Francisco Bay Ferry fleet means providing even more fast, reliable, clean transit for the Bay Area,” SF Bay Ferry board chairman Jim Wunderman said in a statement announcing the commissioning. “SF Bay Ferry is deeply committed to the Bay Area’s public health and air quality, and we’re veryproud of our partnerships with agencies like the California Air Resources Board in meeting emissions standards for our region.”
As the fourth vessel in the Dorado class and the last diesel vessel to be put into service, Zalophus marks an important Zalophus marks an important transition into the next phase for SF Bay
The new passenger ferry was built by Mavrik Marine, La Conner, Wash., and is the fourth vessel in its class, preceded by Karl, Dorado and Delphinus. Zalophus was designed by One2Three Naval Architects and construction management services were provided by Aurora Marine Design.
Like those that came before it, Zalophus has a seating capacity of 320, a fully enclosed upper deck area, bike storage, and an expansive bar layout. The ferry has a top speed of 36 knots when all four engines are in operation.
The boat’s EPA Tier 4-compliant propulsion package includes quad MAN D2862LE48B diesels that produce 1,450 hp at 2,100 rpm to power four HamiltonJet HTX-52 waterjets through Reintjes WVS440 DR DL gears. The ferry, which has 2,000 gals. fuel capacity and runs on R99 renewable diesel, cruises at 40 knots.
Zalophus features selective catalytic reduction (SCR) systems to reduce nitrogen oxide emissions, and it is the first passenger ferry in the United States to be equipped with diesel particulate filters (DPF). The vessel’s four MAN DPF units — one for each engine — filter virtually all the soot particulate from engine exhaust, ensuring compliance with California Air Resources Board (CARB) harbor craft emissions regulations.
This propulsion arrangement was chosen early in the build program to ensure the Dorado-class design could accommodate the SCR and DPF units once approved, a San Francisco Bay Ferry spokesperson told WorkBoat.
Manned by a crew of four, plus one bartender, the 46 CFR Subchapter K ferry has capacity for 320 passengers and 37 bicycles, with a fully enclosed upper deck area. It holds 500 gals. potable water and 500 gals. sewage.
The new ferry features HamiltonJet AVX controls, Furuno electronics, MTU NautIQ alarm and monitoring system, and a Humphree trim control system. Service power is provided by a pair of Northern Lights M99C13 gensets.
Zalophus has begun service on the Vallejo route and is compatible with all SF Bay Ferry routes.
