Where's the bikini line?

In every episode in which the skyline of Bikini Bottom is shown, features such as buildings, houses, and even a large anchor can be seen, this most likely Mr. Krabs' house. In earlier episodes of the series, a red flower arch can be seen, which now no longer appears in the skyline. The Sea Needle, which is the tallest point in Bikini Bottom, is oddly never seen in the skyline. The Sea Needle only appears in two episodes of SpongeBob, Pre-Hibernation Week and Mermaid Man and Barnacle Boy II. The Sea Needle also appears in the video game, Battle for Bikini Bottom where it is shown just outside of downtown Bikini Bottom. In some episodes, a lighthouse appears in the skyline, most likely Mrs. Puff's Boating School. Other episodes feature the Krusty Krab's Marquee. A large fan shaped structure, most likely a rudder from a ship, is seen in some episodes.