Bigger sharks prey on smaller sharks, and they do not make much sound. (srfer.com)
Ancient, small sharks survived an event that killed off most large ocean species 250 million years ago. (sciencenewsforstudents.org)
Then set sail in search of wildlife, keeping watch for bottlenose dolphins, sea turtles, smaller shark species, and depending on the migration season, whales. (uncruise.com)