Not that much time with TSA, but:
1) take taxi, drop you off at gaslamp (from 5th & Broadway south to L), find a place you like,Blue Point, Dakotas, Whiskey Girl, etc.

http://entertainment.signonsandiego....hood=25&page=1
then take a cab back (if you walk to the south end can get a cab at the hyatt or marriot)

2) take taxi, tell them broadway ferry to coronardo, which leaves hourly.
spend time at the del, and surrounding area.

http://www.sdhe.com/san-diego-bay-ferry.html