How does the swim work?
See Swim map. Essentially, you will start in lane 1, head up lane one, under lane rope, head back in lane 2, under lane rope, head up lane 3, under lane rope all the way to lane 8. That’s only 400 metres though! So, you will exit via the ladder at lane 8 and walk back to the start at lane 1. There you will again enter feet first and repeat!