How old must you be to enter the attraction unaccompanied? All visitors under the age of 16 must be accompanied by an adult over the age of 18. Related articles Do I have to pay for a under 3 ticket? What is SEA LIFE Grapevine Aquarium? How can I get the best price? Are there any restrictions for children at SEA LIFE Grapevine? Do I have to invite 30 people?