After trying to fill in the online form to register for this i emailed them and this is the information i received. Hope it may help someone.
Thank you for contacting SeaWorld Orlando. We appreciate your question as it is valuable in helping us improve the high level of service that we strive to provide for our guests. We answer all emails in the order they are received and I apologize that I was not able to answer your email sooner.
Our SeaWorld Parks & Entertainment family of parks is proud to extend our Here's to the Heroes military promotion through December 31, 2012 for active duty military, as well as our coalition forces. The offer is valid for one visit per year to one of our parks (not including Discovery Cove or Aquatica) for active duty military and up to three direct dependents (spouse and children). All eligible dependents, ages 10 & over, must present their active military dependant ID'S to receive the free admission.
For more information and eligibility requirements please visit www.herosalute.com. You will not be able to fill out the registration form due to the Postal Code requirements. Simply bring your active duty ID and proof of dependents to the check in window to receive your complimentary admissions.