Thanks Penny. After I posted this I saw the same site you listed. It looks like it is close to the port, has a shuttle, and is cheap to boot! $6/day with the coupon. I will probably print off the coupon and then if it doesn't look safe when we get there, just go to the port parking garages.
While it would be nice to save a few bucks, it is not worth worrying about your car while you are gone.