Along the coastline, palm trees grow and bear dangerous fruit. Get wet down in an underwater path where you'll be introduced to powerful water currents. Kine is a good swimmer as well as a good partner to have here, and you will need his help to get the Heart Star from an odd creature in this level.
Togezo and Sasuke are both common in this first part of the level, so you can choose to get either the Needle or the Parasol ability if you want (you do have to get the Parasol ability if you want to get the Heart Star, though). There is also a new threat hanging on the many palm trees that line this path: coconuts. These exotic fruits fall to the ground when you get close and will explode when they hit anything, so stay out of their way! Coconuts will be the main obstacle throughout this section, but they are easily avoidable by simply flying above the palm trees themselves. If you still get hit by a lot of coconuts, there are two Health Drinks, one in the middle and one at the end of the area, that should heal up any lost health. The door is located underwater at the right end of the section.
As you plunge into the seas of Ripple Field, you can choose between Kine and Chuchu to accompany you, both being aquatic animals. Kine is the better swimmer, and you will need him if you want to get the Heart Star of this level. Go through the door and you will immediately see Kine comes in handy. In the following section, there are many pipes spewing strong currents that propel you in a certain direction. Only Kine has enough power to swim against these water currents, and the ability to do so will be useful for dodging the Blippers that hang out in these waters. You also need Kine to get a 1-Up and a Maxim Tomato toward the end of this area. Even if you can't get them, there is still a Health Drink above ground at the end of the path, to the left of the door.
Heart Star: Bakasa the parasol creature
There are quite a few Bobo roaming in this area, coming in various body shapes. All of them are still easily defeated, and grant the Burning ability when swallowed. Be sure to enter the first door you come across to enter a room containing a yellow creature with a parasol spinning on its head. This is Bakasa, and it is looking for others similar to it. If you are partnered with Kine and have the Parasol ability, the pose you take when using the ability happens to resemble Bakasa perfectly! If you do that, Bakasa will cheer up and give you the Heart Star at the end of the level.
Return to the main level and continue down the path. There are a couple of Gordos as well as some Bobo that obstruct you. The Gordos will block attacks aimed at the Bobo, so it is better to wait until the Bobo walks close to the Gordo and just jump over both. Halfway through the stage, solid ground gives way to a wide pool. Drop down the first water-filled trench to reach a door leading to a small area with Rick and Coo. Switch partners if you want, then exit the area. Just beyond this pool is the goal door, and there are nothing but a few crab enemies called Kany that slow you down to the exit.