From Marin, Napa, Sonoma:

east on highway 37
exit onto  I-80 west toward San Francisco
exit right onto Maritime Academy Drive
cross Sonoma Blvd (Hwy 29) at red flashing signal light
follow Maritime Academy Drive onto campus

From Sacramento:

west on I-80 toward San Francisco
exit right onto Maritime Academy Drive
cross Sonoma Blvd (Hwy 29) at red flashing signal light
follow Maritime Academy Drive onto campus

From San Francisco, Oakland:

east on I-80 toward Sacramento
cross Carquinez Bridge (use right toll lanes) toll is $3.00
exit right onto Sonoma Blvd (Hwy 29)
left at first yellow flashing signal onto Maritime Academy Drive
follow Maritime Academy Drive onto campus
 
From Benicia Bridge:

east I-780
exit onto I-80 west toward San Francisco
exit right onto Maritime Academy Drive
cross Sonoma Blvd (Hwy 29) at red flashing signal light
follow Maritime Academy Drive onto campus