I've tried many Nauticas, and own a few, but not Competition, so I can't help much there. There are several "how to apply threads" on here. Do a search for them. I'd recommend not to over-apply, but that's just me. Some want and like a large sillage (to be able to be smelled from a good distance) though.
The best advice I can give on application is start with a couple of sprays, and ask someone you trust (family, friends, girlfriend) what they think. If they think it's too light, go for a few more sprays next time.
I work in an office environment, and wear my scents mainly for myself, so I just do 2-3 sprays on all of mine (neck and chest). But others will do up to 5-8. Depends on the fragrance (all have different strengths), and how comfortable you are wearing it.