JET-LAG and alien conditions are the two greatest hazards facing Hongkong Open champion Brian Watts as he prepares for his British Open debut this week. Since his victory at Fanling in February, Oklahoma-born Watts has enjoyed the most profitable run of his career, accumulating earnings of almost US$250,000. A series of consistent displays enabled him to top the Asian Tour Order of Merit. Among the rewards were a 12-month exemption on the lucrative Japanese PGA Tour . . . and a place in the starting line-up at Sandwich. ''Winning in Hongkong and finishing on top of the Order of Merit has opened a lot of doors for me,'' said Watts, who arrived in England on Monday from Tokyo. ''I'm feeling real beat. I haven't slept much for the past few days and I'm having trouble adjusting to the time difference,'' he added. Nevertheless, Watts is not short on confidence. In the last three weeks he has finished eighth, second and third in Japan. He said: ''I'm on a good run at the moment, but the conditions here are so different to what I'm used to. It's like playing a different game. You can't fly the ball all the way to the flag. Because of the wind and the hard fairways you have to improvise alot.''