CHARLESTON HARBOR, S.C. â€"  The biggest bats in the single-A South Atlantic League won't be swinging for the fences during their home run derby -- they'll be swinging for the ocean their league is named after.

The opening round of the home run derby, part of the league's All-Star celebrations, will be held June 18 on the decommissioned USS Yorktown, a World War II aircraft carrier docked at Charleston Harbor, S.C., The Post and Courier reported.

With no outfield wall for the league's 10 best sluggers to clear, the U.S. Coast Guard will judge the distance each hit travels from the warship -- with a crew of paid kayakers and jetskiers on hand to collect the balls from the harbor.

The four best sluggers will move on to the final round of the derby at the Charleston RiverDogs' Riley Park on June 19.