Great Bay(グレートベイ Gurêto Bei) is a stage in Super Smash Bros. Melee that could be considered Young Link's home stage (it is where the player fights him when they attempt to unlock him, and Young Link was the main protagonist in The Legend of Zelda: Majora's Mask, from which this stage originates).
This stage is from The Legend of Zelda: Majora's Mask. This stage takes place in the area in Termina called the Great Bay Coast. In Majora's Mask, the player must travel to the Marine Research Laboratory that is in the middle of the water. In this stage in Melee, players battle on the same platform that the lab is on. The overall design of the lab looks similar to how it appeared in Majora's Mask, except the lower platform is now to the right of the building rather than in front of it and the lab and the platforms have been scaled down. In Majora's Mask, the lab is facing toward the shore, but in this stage, the lab is facing away from shore. To warp between specific locations, and quicksave (Albeit, not in the Japanese version) in Majora's Mask Link must hit an owl statue with his sword. One of the locations of the owl statues in Majora's Mask is on the lower platform of the Great Bay Marine Lab, hence why there is an owl statue in said position in the Melee stage. Like the laboratory, the owl statue also faces the other way around in Majora's Mask.
Majora's Mask is the debut game for the character Tingle. Tingle is seen hanging on a red balloon. If the player wants to talk to Tingle, Link must use a projectile, such as arrows to pop his balloon. First Tingle will pull a landing pose, then when Tingle is on the ground, he will prance around for a little bit, and blows another balloon to float back up to where he was. In this stage, Tingle can be seen hanging on a red balloon. The balloon can also be popped by attacking it, or standing on it long enough. When Tingle lands, he puls the same landing pose, and prances around in the same fashion as he did in Majora's Mask, and then inflates another balloon, returning to his original position.
In Majora's Mask there is a giant turtle that must be awaken to get to the Great Bay Temple. If the turtle is woken up, he splashes upward. In this stage, the giant turtle is retained, but the turtle has been scaled down. The turtle still splashes when rising out of the water in a similar fashion to how he did it in Majora's Mask. The palm trees that are on the turtle are also retained. However, the giant turtle never goes to the marine research lab, and the turtle also never goes back in the water.
The beach of the Great Bay Coast looks very similar to how it appeared in Majora's Mask. The buildings, palm trees, umbrellas with towels under them, etc. have all been retained. In Majora's Mask, beyond the beach are rocky cliffs with rock platforms along the wall. There is also a door, a rocky cliff, and rock platforms, which have also been retained in this stage.
Also in Majora's Mask the Moon is falling towards Termina, and Link has three days or 72 hours to stop the moon from falling. The moon can be seen getting closer and closer as time progresses in Majora's Mask. In this stage in Melee, the moon can be seen falling closer towards the ground as time progresses. When the moon gets to a certain height, four giants which appear in Majora's Mask come and stop the moon, but the giants now push the moon back where it was previously. The design of the moon and the giants look similar to how they appeared in Majora's Mask, but they all have also been scaled down. Also, the moon is facing east in Majora's Mask, but is seen facing down in the stage in Melee. 
There are three tracks for this stage, two of which are usually heard. One track is an orchestrated version of the overworld theme from The Legend of Zelda and the other track is a slightly remixed version of Saria's Song from The Legend of Zelda: Ocarina of Time.  In addition, the Fire Emblem theme plays here when fighting Marth in 1P modes.
It is best to be large because of the setup of the level itself: The more space one can control on the small platforms on the side, the less vulnerable they are to any approach on that area. Staying to the right side of the stage also provides advantage due to the mismatched length of the stage; the area with the turtle has a very long distance to the wall unlike the other. Also, it is possible to perform a stage spike by hitting or throwing characters into the underside of the main platform, resulting in easy KO's, especially for those with decently long forward or backward throws.
The left platform fits only about two people, and this is still a quite small area for two people to be dueling. The bottom right platform is equivalent in size and shape. Above and between the two small side platforms, there is a long platform that is the main fighting area. This platform is flat without any obstacles,and provides an easy KO opportunity: by having a character's back face the bottom of the main platform, using a back throw will result in them hitting the ceiling of the platform and tumbling into the water, taking down the unwary opponent, even at low percentages. Teching the ceiling, however, can counter this. The main platform can fit four fighters, but only about three comfortably. Sporadically, a large, green turtle will appear in either of two orientations to the right of the stage. After about half a minute, the turtle will sink back into the ocean, KOing any players who stand on it. On its shell, it has green grass that provides normal movement traction for characters, but any spots of the turtle not covered by grass will work like a slick surface (i.e. ice or oil). Additionally, the turtle has trees on its shell that players can stand on.
Tingle, from The Legend of Zelda: Majora's Mask, also appears on this stage. Tingle floats around on a red balloon on the right side of the stage, directly above the right-bottom platform. It is possible to pop his balloon by attacking it or standing on it for a while, causing him to flail his arms and legs and fall to the ground or water below. While he is flailing his arms and legs, he can deal 1-2% damage with negligible knockback. It's also possible for Tingle to fall into the water. Rarely, after his balloon has burst, Tingle can fall on the lowest left platform, landing underneath the top platform's ceiling. In this case, when Tingle flies in his balloon, the top ceiling traps him and the balloon automatically pops. Also, if Tingle is close enough to the ground if his balloon pops, Tingle does not land in the background of the stage, so players can pass through him.
 Tournament legality
Great Bay is banned in tournaments; the primary reason being that the stage allows for ample camping opportunities, including circle camping, by allowing characters to easily go from one bottom platform to the other, through going underneath the impassable main platform or over the top of it. Additionally, the main platform can allow for very early KOs from stage spiking, when players fight on the lower platforms.