Ferry from Coronado to Petco Park
Looking to do something different? Drive over the Coronado Bridge and take the ferry back to the park! You’ll avoid painful traffic and costly parking. The ferry only costs $3.50 per passenger and is a brief yet beautiful trip across the harbor.
The ferry leaves Coronado from the Ferry Landing Marketplace every hour on the half hour (so 3:30, 4:30., 5:30 etc.) and arrives at the Broadway Pier, by the Midway and cruise ship terminal.
Coming the other direction, the ferry leaves every hour ON the hour. Extend the pleasure of a Padres game with a nice stroll through Seaport Village and celebrate the beauty of San Diego. Or if your feet are killing you, take a pedicab (those guys on bikes).

Related:
Petco Park's address