Mariscos Nine Seas food truck isn't listed at sdfoodtrucks.com. It's a curious omission, considering that Nine Seas (3030 Grape St. in South Park) not only offers some of the best Mexican-style seafood in town but is also one of the best local food trucks regardless of style.
Nine Seas' "Specials" menu describes its green-sauce ceviche (available with either fish or shrimp) as having "Avery Interesting Flavor." While the spelling may leave something to be desired, the flavors do not. Like most ceviches, Nine Seas' features seafood "cooked" in acid (in this case, lime). Nine Seas' version includes minced onion, finely diced tomato, herbs and a generous chunk of perfectly ripe Hass avocado with chile-lime seasoning.
But as good as all of that may be, it's the intriguing green sauce that provides the unique flavor. In this purée of herbs and aromatic vegetables—likely including onion and garlic—it's the basil that surprises and delights. You don't expect that in Mexican cuisine and certainly not from a taco truck.
Another superb option at Nine Seas is the Campechana, a Mexican take on the seafood cocktail. Nearly every one of Mexico's coastal regions has its distinct version of the Campechana, though, as its name suggests, it originated in the Mexican state of Campeche in the Yucatan. Nine Seas' version features shrimp, oysters, octopus and fish, as well as finely chopped onions and peppers. But it's the soupy sauce that makes the dish. The strong individual components—lime juice, ketchup, Clamato (tomato-clam juice), hot sauce—meld to form a single flavor that's at once sweet, sour, spicy and savory. The seafood bits, delicious as they may be, are just excuses to enjoy that sauce.
Nine Seas' fish tacos are another highlight. Its shrimp Gobernador, octopus, fried and grilled fish tacos are all good. The fried fish taco suggested the source from whence Ralph Rubio might have nicked his idea. Yes, this was fish fried in fat with a mayonnaise (which is to say, fat-based) sauce on it, and yet it didn't feel particularly fatty. It was rich, yes, but also clean.
The grilled fish taco—swai (Vietnamese catfish), if I don't miss my mark—was surprisingly tasty. Swai is not a fish I often buy, nor one I particularly like. Frankly, the more you know about swai, the less likely you are to want to eat it. But Nine Seas managed to coax a lot of flavor out of that beast of dubious provenance.
Perhaps the best of the tacos, though, was the octopus. The supple texture and deep, meaty flavor of the creature, which is almost always a favorite of mine, was perfectly complemented by the sweetness of the onions, the peppers and the grassiness of the celery. Nine Seas' octopus tacos are street food at its best.
In fact, that statement can be taken a step further: Nine Seas' food is street food at its best.