Once you get to the giant hill with the green pipe on top, go to the top left platform and keep going left until you reach the warp star. You will be inside the hill (this is also the only healing on this map) but go inside this warp star. You then go to a platform in the sky with two lights blinking and a warp star, these lights signify where you teleport out of when you enter the warp star. Just enter this warp star as this one doesn't matter as they both lead to the same spot. Move right until there's another warp star, and more lights. Now you have to time it so you go to the above spot. Jump to the right until you reach another warp star. This time you are trying to time it so you reach the bottom. If done correctly go into this warp star. This brings you to a bunch of platforms spelling MARINA. Jump over until you reach the last A, and there is another warp star, as well as the gold gem and 3 locations the light is going on, but you will wan't the middle (obviously), also be weary as this last one moves quickly and can be hard to time.
Note: If at anytime you either time it incorrectly, or fall off on the MARINA platforms, you will HAVE to restart the level as the warp stars disappear as you go through them.