Glow-berry Crown

There should be a lighting source specific for layers under 0. Because coal cant generate naturally in these layers, you would need to bring many stacks of coal and torches along with you in order to have a successful trip. My suggestion would be a glow berry crown. this is diferent from a mining helmet because it would be in the style of minecraft, and would utilize an item that already grows in the area, making glow berries more useful and sought after. This would also be better than torches because 1. it raises the difficulty in that you cant see where you came from and in that it would take up an armour spot, 2. it would most likely be more expensive (also why it is better than simply carrying a torch), 3. it would enhance gameplay by increased emersion. This item would not be op if it was made to be expensive and take up an armour spot (forcing the player to chose between breathing underwater, increased defence, or light). This item also has the potentential to look very beautiful, and lots of players find it very appealing to look cool/pretty. :)