Last year, two of my friends starting teaching at secondary schools "without" any teaching cert. Whether u need to take the PGEC depends on the headmaster's decision. If the school principal sees u're capable of teaching the students, then he is willing to hire u even u don't have any edu cert. But let me tell u some more pagmatic pts. First of all, PE is not a main subj at school but there is always lacking human resources. So ur qualification is better than enough to take a PE teaching post. Say, if u don't teach well, it will NOT bring harm to students' other more impt subjects, like Maths and Eng. But if u really teach well, it is just a bouns to the school as the headmaster has one more thing to promote his school.
Second, a couple of yrs ago in HK, a secondary school teacher was not asked to possess any cert edu, just BA was enough. But the HK govt perhaps felt the dropping teaching quality, so the govt demanded higher entry requirements--BA plus cert edu. As for the principals, what troubles them most is they fail to find someone to fill the place. AS a result, the principal has to ask the existing employees. When I was at high school, my form teacher often took up some PE classes. But what I try to say to u is that u should listen to ur friends. self-soliciting urself to schools. Or u can go to http://jump.mingpao.com/cfm/JobSearch1.cfm , a web site run by HK's most renowned newspaper and consists most of the edu posts. Good luck.