I don't see it as sinful for SSPX priests to go to Sea World. It seems Puritanistic to assume that it's sinful. Recreation is not an unreasonable thing for Catholic priests to engage in.
It reminds me of my ancestor, Stephen Hopkins, who sailed on the Mayflower in 1620 along with a lot of Puritans. He was Anglican. Well, he actually opened an alehouse right there in their little town of Plymouth, much to the horror of the Puritans there. He had owned an alehouse back in England. He got into trouble a few times with the Puritans, who accused him of selling alcohol on a Sunday. Such is the Puritan mentality.