If you're concerned about your swim, check out Total Immersion. You can find the videos on YouTube. Distance swimming boils down to technique & being in decent cardio shape. If you're in shape, the 1.2 mile swim should simply be a warm-up by the time you attempt the 1/2 Ironman race. Get in the habit of running after you bike. Every time you get off your bike, lace up the shoes and go run a quick mile or two. This'll help. Good luck.