The sea is beautiful, but sometimes it is dangerous because some animals are poisonous. Therefore, when we dive, we must be careful not to hit the animals that we don't know, or beasts that are poisonous.
The sea is beautiful, but sometimes it is dangerous because some animals are poisonous. So while we dive we must be careful not to touch the animals that we do not know. Or poisonous animals
The sea is beautiful, but sometimes it is dangerous because of some kind of animal poison. So while we must be careful not to hit the US black animals that we don't know or animals with poison.