Undercover Tourist is now offering savings of up to $39 (versus the gate price) on a range of SeaWorld Orlando tickets for use in 2021. It also gives information on their site regarding any necessary ticket reservations. 

Guests must visit https://seaworldentertainment.com/reservation/ prior to their visit to make a reservation. For tickets involving multiple parks, you must make a reservation for each one.

Undercover tourist offers the option of e-tickets or they offer free shipping for tickets.