Scuba diving with potentially dangerous animals is about respecting the animals and not touching them. But there’s more danger in scuba diving from other things that are not related to dangerous animals. These include scuba diving with health issues, diver errors and equipment failures. But animals that are considered a danger to humans underwater include sharks, barracuda, blue-ringed octopus, scorpion fish, stone fish, lionfish, sea snakes, fire coral, stingrays, jellyfish, flower urchins and cone snails. But in reality, none of these pose a serious threat to scuba divers if treated with adequate respect and caution.