Honestly, if you have a 1480 I'd resit; you really need to get 1500+ at least to stand a chance, 1480 would be the absolute minimum if your application was 100% perfect in other areas, which probable isn't going to happen.
As for sports, most big universities try to get the junior internationals for their main sport; for instance the Junior World Rowing Championships were just a couple of week ago, and most of the GB team will be going on to study at Oxbridge in October. It's not fair but it happenes, and as a 16 year old thinking about university for the first time, you known that if you excel in a sport you have a big advantage over normal candidates.