THE ACFT CRASHED OFF THE DEPARTURE END OF THE RWY IN A SWAMP DURING AN ATTEMPTED GO-AROUND. THE PILOT SAID THE APPROACH WAS NORMAL BUT THAT THE ACFT FLOATED MORE THAN NORMAL. A GO-AROUND WAS INITIATED. THE PILOT COULD NOT REMEMBER IF THE ACFT TOUCHED DOWN BUT FELT THE ACFT DID NOT CLIMB PROPERLY. THE ACFT HIT A TREE AND CRASHED. ACCORDING TO A WITNESS AS THE ACFT TURNED FINAL THE PILOT BANKED SEVERAL TIMES, AND THE ACFT SPEED WAS TOO FAST FOR A SLIGHT TAILWIND EXISTING AT THE TIME. THE PLANE TOUCHED DOWN NEAR THE DEPARTURE END OF THE RWY. POWER WAS APPLIED AND THE ACFT GOT AIRBORNE IN A STALLING FASHION AND CRASHED IN THE SWAMP ACROSS THE ROAD. DURING INVESTIGATION TIRE MARKS WERE FOUND ON THE LAST 250 FT OF THE RWY AND CONTINUED THROUGH SOME HIGH GRASS. NO TIRE MARKS WERE FOUND ON THE ROAD. THE ACFT WAS 200 FT PAST THE ROAD WITH THE LEFT WING SHEARED OFF. THE RWY IS ABOUT 1400 FT LONG WITH A HIGH POINT IN THE MIDDLE SLOPING DOWN TO BOTH ENDS. THE ROAD PERPENDICULAR TO THE RWY IS 50 FT FROM THE DEPARTURE END.