For three hours, more than 40 sand sculpture teams shoveled, shaped, and lugged water as hundreds of entertained visitors looked on. The results of their efforts were quite impressive.   Kim Gil Man has won the Sand Sculpture contest three times i the past 10 years.  During the week, he works at an industrial chemical plant, but on the weekends you can often find him on Haeundae Beach created his sand masterpieces.  This year, his team was one of two special invited guest teams. There were a handful of television crews on hand filming the contest and countless photographers shooting away as contestants toiled in the sun.