The commercial pilot was shuttling fisherman between lakes in the float-equipped airplane under Title 14, CFR Part 135, when the accident occurred. The pilot reported that he planned to shuttle two passengers at a time, but felt the wind was sufficient to take four. He said that during the takeoff roll the wind went calm, and that the glassy water extended his run farther than expected. The pilot said he felt there was not enough lake left to stop the airplane before colliding with the bank if he aborted the takeoff, and decided to continue the takeoff. He said the airplane lifted off the lake about 20 inches, and collided with the bank. The pilot said there were no known mechanical anomalies with the airplane prior to the accident, and that the airplane sustained fuselage damage during the accident.