Bubble ring

The Bubble Ring is an underwater object appearing in Super Mario 64 and its remake, Super Mario 64 DS.

Super Mario 64 / Super Mario 64 DS
In Super Mario 64 and Super Mario 64 DS, they are seen only in the ninth course, Dire, Dire Docks. When Mario swims through a Bubble Ring, it will replenish one wedge of his health meter, and a number will appear above Mario. This number represents the amount of Bubble Rings Mario has passed through. When Mario swims through five Bubble Rings, he will be granted with a Power Star.

Bubble Rings were required for Stars 4 and 5 in Dire, Dire Docks. In Star 4, "Through the Jet Stream", Mario must swim to the other side of the tunnel to find a jet stream spraying out Bubble Rings. After Mario collects five of these Bubble Rings, a Power Star appears above the jet stream that Metal Mario can collect. In Star 5, "The Manta Ray's Reward", Mario will find a Manta Ray swimming around underwater and leaving a trail of Bubble Rings. Mario must follow this trail to collect five Bubble Rings and make the Power Star appear.

Mario Party 4
Bubble Rings also appear in Mario Party 4 in the minigame Manta Rings.