Delta Airlines has a $399 hurricane season discount for flights from multiple airports in California to the Cayman Islands. I see this fare from LAX, SFO, SNA Orange County, SAN San Diego, SJC San Jose, and SMF Sacramento.
Flights route from California to Atlanta and then ATL to GCM, Grand Cayman Islands. Sacramento routing is two stop flight via LAX and ATL at $403 round trip.
The base fare is $256.00 and earns 1,280 Skymiles for round trip flight.
Delta Airlines San Diego SAN – GCM Grand Cayman Islands
$398.25 Saturday, Sep 19 –Saturday Sep 26, 2015
United Airlines has a similar fare at $403, but routings I saw at saw at this fare from San Diego required an overnight in Houston IAH on the return.
United Airlines San Francisco to Grand Cayman Islands
$398.25 Saturday, Sep 19 –Saturday Sep 26, 2015
United Airlines economy G class SFO-IAH-GCM without overnight layover.
