The quickest way to get to the park from downtown is by car but if that’s not an option, you can do it via public transit - but ONLY during the week. We had decided not to get a rental for this trip as it was split between San Diego proper and Coronado Island, and most of our sightseeing would be in the city. If you’re in a similar situation, this is what you do:
Get yourself a 1-day transport pass: we bought ours at the Transit Store (corner of 102 Broadway and First Avenue; open only during the week) and it comes on a Compass Card that can be reloaded as needed. See this website for other purchase locations, how to reload it, and how to use it:
Then walk 5-6 blocks down Broadway to the Santa Fe Depot (or a Green Line trolley stop closest to you) and jump on the Green Line going in the direction of Santee to the Old Town Transit Center.
Here you’ll transfer to the #28 bus to the Shelter Island Drive stop (G on the attached map) on Point Loma, and then transfer to bus #84C out to Cabrillo NM.
To come back, just reverse the process, picking up the #28 bus at point F on the map, and the Green Line trolley going in the direction of 12th and Imperial.
To use your card, just tap it on one of the card-reader pads alongside the tracks before your trolley arrives, and again on the same pads located at the front of the buses when you get on.
Bus route Map:
The good news: this is an excellent opportunity to combine visits to the park and Old Town on the same day - which we did. Do Cabrillo in the morning and OT in the afternoon.
The less-than-good news: the 84 bus DOES NOT RUN ON WEEKENDS OR HOLIDAYS. The schedules of the two bus routes also do not always coordinate well so you may have a bit of a wait between transfers, and service to/from Cabrillo occurs only once an hour so watch the time if your schedule is tight. There was a little coffee shop on the corner of the transfer point to the 84 route so we grabbed some joe to pass the time between buses.
Many sailors arrive by Nuclear Submarine. Most likely this will not be an option for you.
If you have to rely on public transportation, the 26 bus will bring you to Cabrillo NM.
However, if you want to explore the tidepools or see more of the Point Loma area as well as visiting Cabrillo N.M., the best way of getting here and exploring is by car.
The road leading to CNM is an interesting one. You will drive through U.S. Military property. Also up here is Fort Rosecrans National Cemetary. It is open to the public and a drive through offers spectacular views of the city and the ocean. Just left after entering the Cemetary, you'll find a section devoted to historical characters important to San Diego's past.