Informed by a persistent killjoy that a six-foot gator was seen two days earlier in the same part of the Chattahoochee River, the Kirby family reached a quick consensus. "I think we'll be getting out now," said Chris Kirby, 28, of Stone Mountain, who had planned a relaxing Friday afternoon wading in the Chattahoochee's 50-degree waters with his wife, 9-month old daughter and chocolate labador. News of the gator -- spotted Wednesday by a pair of joggers off the river's bank at Cochran Shoals near the I-285 bridge --- altered their plans.