Don't get frustrated with getting winded, as you find your pace & add distance your breathing will improve dramatically. You'll find you won't be getting nearly as winded swimming, but you'll also find you won't get as winded doing other things too (climbing stairs, carrying things, etc.) & your endurance for other activities will increase too. Remember, you have plenty of time to prepare - like the race itself training for it is a distance event, not a sprint. Concentrate hard at the beginning of your workout on pace & make yourself lengthen your stroke, once you're at the point in the workout where you've been getting settled in to the pace you can concentrate on form, breathing, etc.

Holly - thanks for the kind words, I just hope what I've been telling you has been of at least a little help & is making sense in the water. jkbsmom & I are also already friends on here :-)

I'm not an OW swimmer, but, like you, I was a sprinter in high school. I now swim 5ks, and I'm working on developing as a short, mid-range, and distance swimmer. What I've found to be helpful in making the transition is training in sets that get longer over time. So for example, you could develop 4 sets totaling 450/set, and work through those wherein the longest distance you swim is 100 yards in any one part of the set, i.e. 100 sprint, 100 drill, 100 kick, 100 pull, and 50 sprint. Eventually, you'll get to the point where you can move those 100s to 200s, and then full 450s. You can mix in different strokes if it helps break things up, and your endurance will still get better. Work up to half miles from there, and then full miles (1800 yards). When you're swimming a full mile, you can work in your taper sometime before the big race and go fast.

I justclicked on open water swimsand then my state.

I signed up for a relay tri in June! I'm doing the swimming portion, it's only 800m but in open water. Makes me crazy nervous, but I am hoping it will just be fun. I don't have a lake to train in, so it will be all pool swimming and maybe a couple times out in open water... am I nuts? That's what I'm thinking... I'm nuts... but can't let my other team-mates down! Just finishing will be a good start for me, too!

Sounds like you have a plan to build your endurance, so I'll just add some things about OW swimming you'll need to think about. Bilateral breathing is a big one if you don't already do it. Swimmers that breathe to only one side tend to drift; bilateral breathing helps you stay straight. Practice sighting, which is looking up ahead for the next buoy or marker. You should be able to bring your head up and sight, without slowing you down too much. Kind of like a lifeguard approach stroke. Lastly, be prepared to get banged around if it is a group start. People will be swimming over you, you'll be swimming over others, elbows and knees and feet and hands everywhere. Usually it sorts itself out as people settle into their pace and room is opened up.