THE HOMEBUILT TEENY-TWO ACFT WAS BUILT WITH A 40 HP, BRITISH RELIANT, HAWK AE ENG, RATHER THAN A VOLKSWAGON ENG WHICH BUILDERS NORMALLY USED. IT HAD BEEN FLOWN ONLY ONE TIME BEFORE THE ACDNT FLT. THE 1ST FLT WAS MADE IN COOLER TEMP CONDS WITHOUT INCIDENT; THE 2ND FLT WAS MADE ON AN 81 DEG DAY. THE PLT RPRTD THAT DRG TAKEOFF ON THE 2ND FLT, ALL SEEMED REASONABLY NORMAL UNTIL AFTER THE ACFT LIFTED OFF AT ABT MIDFIELD. AFTER IT HAD BECOME AIRBORNE & TRAVELED ABOUT 3/4 OF THE WAY DOWN THE 3200' RWY, THE PLT FELT THE ACFT 'STAGGER A LITTLE.' HE CHECKED FOR FULL THROTTLE & LOWERED THE NOSE TO PICK UP AIRSPEED. HOWEVER, AS THE ACFT CONTINUED OVER A SWAMP AT THE END OF THE RWY, IT STARTED TO SETTLE & WOULD NOT SUSTAIN FLT. SUBSEQUENTLY, IT TOUCHED DOWN & CRASHED ON THE SWAMPY TERRAIN. NO PREIMPACT MECHANICAL FAILURE OR MALFUNCTION WAS RPRTD.