According to reports from Spectrum News 13 an email went out from SeaWorld to its Ambassadors (AKA employees) stating that masks are no longer required if an employee is fully vaccinated.
The only other details able to be shared at this time is that employees need to provide proof of vaccination in order to take advantage of the opportunity to go maskless. And according to the same report, guests will be aware who is vaccinated because they will have a sticker on their name tag identifying the ability to go mask free. Sea World is reportedly still adjusting these and park rules periodically. We will check back at a later date to see more updates! This new rule goes into effect on Tuesday, May 25th.
Source: Spectrum News 13