Check out the Atlanta Powerboat Club website, www.atlantapowerboat.com ! There are several lakes around... The biggest that's near Atlanta is Lanier - plenty big enough for 30' boats... Allatoona is where we hang out mostly.. It's a smaller lake but GREAT people!!
Lanier is about 1 hr from Atlanta. Allatoona is close to the same, maybe less. There are other lakes like Oconee and and... oh I forget!
Savannah is 3.5 hrs, Hilton Head is 3 hrs... Lake Hartwell, SC is 2.5 hrs away...