Answer:
I am in the middle of water but am not an island.
I can wake you up in the morning but I require no electricity or winding.
Good memory, skin like the sea. A great beast I am, yet vermin frightens me. What am I?
I am Invisible Man's drink at snack time
I fly when I'm on and float coming off.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.