On this day in 1988 Southwest Airlines unveiled a Boeing 737-300 painted in an unusual livery.
Southwest Airlines and the US State of Texas SeaWorld of Texas joined up to promote Texas as a major tourist attraction.
Southwest's website said: "Southwest becomes Sea World of Texas' official airline and creates "Shamu One," a Boeing 737 painted like Shamu the killer whale. Later in the year, Southwest becomes the official airline of SeaWorld of California."
This image shows three Shamu liveried 737s. Presumably the last is for the Orlando SeaWorld branch.