When you are a big predator, matching your surroundings is the key. Barracuda feed on small and medium-size reef fishes. Barracuda have gotten a bad reputation for two reasons. They have a big jaw lined with sharp teeth, and they are curious. If you are swimming along and feel like you are being watched, you probably are.
Barracuda tend to follow divers around the reef.
No harm intended, they are just inquisitive. Barracuda never bite people on purpose. The only attacks involve spearfishing or a mistaken identity in murky water. In temperate and tropical oceans.