Bowser's Sub

From the Super Mario Wiki

Bowser's Sub is a submarine featured in Super Mario 64/DS. It played a prominent role in the first mission of Dire, Dire Docks, entitled Board Bowser's Sub. Here, Mario had to climb atop the sub and reach the Power Star at the very tip. Though little is known about the sub, it can be assumed that Bowser's troops were in it. The sub disappeared after Mario defeated Bowser in the Bowser in the Fire Sea level.

Watercraft
Bessie Bass's Battleship | Black Skull | Blackbeard Koopa's Ship | Bowser's Battle Yacht | DK Cruiser | DK's Boat | Daisy Cruiser | Ding Bell | Gangplank Galleon | Hover Craft (DKC3) | Hovercraft (DKR) | Motor Boat | MSS Sea Star | Peapod | Pirate Ship (3 on 3) | Pirate Ship (SSBB) | S.S. Caviar | S.S. Chuckola | S.S. Flavion | SS Tea Cup | Sinister Star | Sunken Ghost Ship | Sunken Ship | Turbo Ski
Submarines
Bowser's Sub | Doomsub | Knautilus | Koopilus | Marine Pop | Yoshi Submarine