Ballerina, we went there in our casual clothes and saw many other diners there dressed the same. It's a family seafood restaurant, not particularly upscale-- certainly not as nice as Napa Rose, and I think I'd consider Ralph Brennan's to be nicer, as well.
To be honest, we were disappointed in the quality of the food and the lack of overal ambiance. I had the impression from a guidebook that it would be all Pirate-y and themed, but it's not at all. There was an abstract metal ship sculpture hanging over the chef's bar, and that was the extent of the "Captain Hook" decor. We found the food to be mostly adequate but very overpriced, and I've never had sea bass that was so overcooked and dry. The service was pretty good, probably because we had reservations at the first dinner seating so were one of the first tables seated.
On the other hand, I've heard other people say they really liked it. I hope you have a good experience!