I generally don't eat for the few hours immediately preceding a competition - I find that I feel lighter and faster when I'm on an empty/nearly-empty stomach, and I don't have to worry about my body protesting when I go to compete. Prior to that, I'd suggest eating whatever makes you feel best.
For the record, my experience is that the above applied pretty well to just about any sport - primarily tennis in my case, but also swimming/running/biking at any kind of significant intensity. Generally eating too much in the hours before competition would leave me feeling heavy and sluggish - or at least this was the case when I was playing tennis competitively in the past. During the event itself water was generally sufficient - though for longer events something with a little actual nutrition might be helpful.