The swimming events in the Asian Games was important to me because of my two pamangkins who are swimmers themselves. In fact, I bought my tickets to this sporting event months before it was actually held to make sure that I'd be able to see it.
There really wasn't that much choice of seats because they are only on one side of the pool. The other side was reserved to delegates and others with special pass. So my only choice actually was either a seat at the lower or the upper row, and the left end or the right end of the bleachers.
My wife and I chose seats at the lower row to get as close to the action as possible. The seats were also somewhere midpoint of the pool so we could have an acceptable vantage point whichever end the swimmers would start or finish. If I have chosen a seat at one end of the pool, I would probably get a good shot of the swimmers as they jump off, or when they finish, but then, those would be all the shots I could get. It would have been very limiting to shoot the rest of the action from that viewpoint.
It should be fairly easy to know the peak moments in swimming because the swimmers' actions are repetitive and basically follows a rythmic pattern. What makes it difficult is the excessive splash of water around, that a lot of times they cover the faces of the swimmers even when they resurface for air.
Breast stroke is probably the one with the least splash because the swimmers arms and legs remain mostly underwater when they do their strokes. Such movements make tham virtually just glide on water. With butterfly stroke, there's plenty of splash when they do that dolphin kick and both arms paddle at the same time. But the swimmers are able to lift their bodies above water from head down to most of their upper body so you still get a fairly good view of the swimmer in action.
Freestyle (front crawl) and back stroke (back crawl) are perhaps the trickiest to shoot succesfully. Often times, you only get to capture arms above the water. With freestyle, the swimmers have their faces down under water and just pivots from time to time to gasp for air. With backstroke, although they are facing up, there is still a thin layer of water on their faces most of the time plus the excessive splashes.
OTHER HIGHLIGHTS TO SHOOT
Another peak moment to shoot should be when the swimmers jump-off from their platforms. However, you really need to be close to the action to capture an effective photo. The tricky part is that this action happens just once for every heat so you'll have to be as prepared as the swimmers are when that gun fires. You won't get a second chance. Of course, there will probably be other heats but sometimes, a particular jump off is more important than other all other jump offs. For example, the one for the gold medal race.
What about the celebration when a swimmer wins? From what I have observed, it's not that exciting. Even when they have broken a record, the swimmers' acts of jubilations doesn't seem to be as exciting as when a football (soccer) player scores a goal or when Michael Schumacher jumps up from the podium before or after receiving his trophy. Often times, they just raise a fist, or both fists, and smile - no explosion of emotions. I'm not saying they don't do more than that because they do, but such are rare occurences so you still better have to have yourself and that camera ready.
Swimming is a fast-paced and an exciting competition to watch and photograph, but a rather tricky one. Not difficult but tricky. Each heat lasts for just a few minutes so opportunities for great sports action shots are limited. Choice of vantage point and to have a really fast long lens is most ideal.
The photographer should be ready before the competition starts and should have everything pre-planned. As mentioned above, each heat lasts for a few minutes - you won't have time for trial and error because, most of the time, you won't have a second chance.