From the North: Take I-5 Freeway south and exit on Clairemont Drive/Mission Bay Drive. Make a right onto Mission Bay Drive. Then head north on Mission Bay Drive or south on East Mission Bay Drive
From the South: Take I-5 Freeway north and exit on SeaWorld Drive. Make a left onto SeaWorld Drive. You can turn right onto East Mission Bay Drive for park access or continue down SeaWorld Drive to SeaWorld and Mission Beach
From the East: Take either I-8 west of 94 west to the I-5 north. Then exit SeaWorld Drive. You can turn right onto East Mission Bay Drive for park access or continue down SeaWorld Drive to SeaWorld and Mission Beach
Public Transportation: Access to the beach is limited on Public Transportation. Bus Route 30 will take you to the northern end of Mission Bay and into Pacific Beach. Bus Route 9 passes by SeaWorld on its way to Pacific Beach. Bus Route 8 will take you along the coasts of Mission Beach and Pacific Beach. Bus Routes 35 and 923 take you into the heart of Ocean Beach.
Here is a snapshot of the map showing Mission Bay and Mission Beach, easily accessible from San Diego freeways.