I live in Brunswick and I work on Jekyll Island. There are four restaurants that serve seafood. I have not visited one of the them, Lattitude 31, in many years so I don't know anything about it. SeaJay's, Blackbeard's, and Zachry's are all casual dining restaurants with a variety of seafood. I have had good meals at all three restaurants in the past year.
St. Simons Island is a 20 minute drive from Jekyll and is well known for it's dining. As someone previously posted, The Crab Trap is excellent. The Crab Trap sells primarily fried foods. Next door is Crab Daddy's which serves seafood in other manners but no fried options. Both restaurants are owned by the same people. Another favorite of mine is Barbara Jean's. Barbara Jean's offers "southern" cooking with some seafood options. They have some of the best crab cakes that I have ever tasted.
I'm happy to answer any other questions that you may have about the area.
Brenda