DUBUQUE CHALLENGE. Speedboat racing event. Organized in 1997 by John Lentzkow, the race occurred after promoters of THUNDERFEST announced that they could no longer afford to direct the event without a sponsor. Held in June, the Challenge was to differ from Thunderfest because of its focus on racing with fewer side shows and a course closer to the river bank. There would be two types of racing, outboard performance craft (OPC) with five classes and drag boats. OPC races were over a half-mile course. Drag boat races offered head-to-head double elimination competition.