In the third "room" of the Lair of Kharyon stage, go with the water's flow clockwise until you reach the bottom part of the room. Once you do, swim up as far as you can, and the wall should stop you and push you upwards to a doorway. In the next room, swim all the way to the right, then swim upwards and grab the 1-UP. Now, leave the room via the door right next to the 1-UP and then head back through the door. The 1-UP reappears! You can do this trick until you have 99 Lives, and then return to the stage later in the game and do it again if needed!