Buoy Base Galaxy - The Secret of Buoy Base

Welcome to the Galaxy!
Mario
We land on near the base of a fortress in the middle of a pool of water. The Buoy Base music plays, which is one of my favorites. A nearby Gearmo tells us, "This here's a floating fortress. We call it Buoy Base. But nobody's using it now, so we're just here for upkeep." First, we're going after the secret Star here. We dive underwater, where the music changes. There are Bloopers to avoid here. On the side of the bottom of the pool is a pipe in a cage. How can we break this cage? With a Torpedo Ted, of course! There are a couple of torpedo blasters underwater, so we approach one and lead a Torpedo Ted into the cage (it has the same homing mechanism as the Bullet Bills.) Once the pipe is freed, it produces a vortex, that, if we get close enough to the top of the pipe, will draw us into it. The pipe takes us to the other side of the planet, so that if we look at the ground, we'll see, through the water, the underside of the planet. We land on a yellow path above the water. If we fall in the water, we'll have to go through the pipe to get back here again. Going along the path, we have to deal with Bullet Bills. We make our way on the path and take a hit from both a Bullet Bill and an Amp. We reach the end and see a Green Star in a cage. We lead a Bullet Bill to the cage to break it and get the Star.
Green Star Get #1!
Star Get #40, 3 Coins, 1898 Star Bits, 17 Lives

Interlude
We land on the deck and discover a new chapter is available in the library. Polari says, "You rescued a Green Power Star! These stars have a special power. Ask the Green Lumas about them. After all, they will transform into Green Power Stars someday!" We've collected our first Green Star and the first Green Luma has appeared near the translucent green Launch Star. Collecting the remaining Green Stars will bring back the Green Lumas and make the green Lauch Star work. This will allow us to access the Trial Galaxies, which are difficult challenges based off of objectives we've seen before.

Luigi
As with Mario, we dive underwater and lead a Torpedo Ted to the caged pipe so we can access it. We appear on the other side of the planet and take a hit from a Bullet Bill before leading one into the cage for the Green Star.
Green Star Get #1!
Star Get #40, 3 Coins, 2171 Star Bits, 13 Lives

Interlude
The Green Luma we found needs the doorway (Green Launch Star) opened with two other Green Lumas.