Arr SanDiego ex cruise ship about 10am and have Southwest flt home around 4pm. Will Southwest let me checkin baggage 6 hours early (we hope to spend day in the city iso hanging around airport) and if not....are any baggage lockers left in this world or anywhere at airport to leave luggage? (I tried this 3-4 years ago and was then told Southwest had 2 hours prior to departure max checkin time) Any ideas? Thanks Dennis