This is a well-established and good place: http://www.mavericksouthernkitchens.com/slightlynorthofbroad/reservations/?gclid=CJCxu6S4s7ECFWYbQgodMSkAMQ

We ate at Fleet Landing and it's right on the water. Good and casual.

We also ate at Hanks. Very good and a little less casual.

You could eat on Shem Creek for the "water". If you want great food, you have a lot to choose from in Charleston proper (I assume you know that Charleston is not "on the water"), and there are probably close to a hundred threads on places to eat in Charleston if you do a search.

Charleston is in between 2 rivers, so there is water. But I wouldn't drive all the way from Kiawah to go to Fleet's for supper. Have a cocktail there and enjoy the view.

There are many (MANY) places from which to choose. Not stuffy, but delicious, is FIG on Meeting St. make a reservation. You won't get a table without one. Other favorites include High Cotton, SNOB, Anson, Tristan, McCrady's for trendy, 82 Queen, or Magnolia's for traditional. Hank's is great for seafood, but all the places I listed have fresh seafood. It's a big deal around here.

Also, Fat Hen on John Island is excellent, and closer to Kiawah.

I don't know if this is too far for you to go from Kiawah, but our favorite seafood place is The Wreck of the Richard and Charlene in Mount Pleasant. It's "on the water", definitely not stuffy (paper plates) and has the best shrimp, red rice and banana pudding you'll ever get. Be sure you google it and get the directions down accurately as it is very hard to find - doesn't even have a sign! Otherwise FIG is one of absolute favorite restaurnts ever. You won't regret going even if it doesn't have a water view. Local food, local flavor.

I second Fat Hen, we love it and it would be very convenient to Kiawah. I would suggest making reservations well in advance, but they also leave some tables for walk ins. We have never had to wait more than about 30 - 45 minutes. Great food, fun atmosphere.

I'll insert here a recent report on Husk.
DD and DBF went last week. They ARE foodies--manage a 5* restaurant (managing partner and general manager) and go out to eat at the best places in Denver on a regular basis. They went with a friend who owns several restos here in Charlotte, (and had owned a resto with DBF). They had heard all the hype. It was pretty "meh", very disappointing.
I had read that also on here within the past year, and after they reported back, I told them. They had made the reservations a week ago for the cancellation list, so the word isn't out!! They got in on a cancellation. So, buyer beware.

And the Wreck is the favorite of many. Take cash if you go--and can find it!!

Gretchen - the Wreck now takes credit cards!

And it's not hard to find with GPS.You just have to know what it looks like since there's no signage.

I've been to Husk when it was great and when it wasn't. With so many great places in Charleston there's no reason to take a chance.