About 1,200 weekend visitors to Santa Catalina Island returned home about 12 hours later than they had expected to due to high winds and rough seas in the San Pedro Channel. Wind gusting to 40 m.p.h. and unusually choppy seas halted all ferry, helicopter and airline service to the mainland, and Oley Olsen, who manages two hotels at Avalon, said it was good for business. "We had 90% occupancy in both hotels," he said. "We average about 50% on Sunday nights in winter."