Fishing, hunting, camping, hiking or hang-gliding, the International Sportsmen's Exposition will have it all this weekend at Cal Expo. Exhibits and demonstrations will stretch four buildings, as hands-on activities cover outside. Casting competitions and fishing tournaments will be available. Casting tarps stretched 100 feet across the floor of building C, will provide the forum for fellow anglers. A large fish-filledaquarium will be featured for live demonstrations. Prizes include new fishing equipment. Clinics with professional anglers and hunters will be held for the home amateur to learn tricks of the trade. Classes include camouflage, duck calls and hunting laws. DockDogs will perfo