All Lights

Do you remember your Open Water theory, that water absorbs colors?  Only 5 meters of water starts to absorb a noticeable amount of red, go deeper and you`ll lose even more red and the other bright colors (Red/Orange/Yellow/Green/Blue in this order).  Lights are important to correct the colors, or even just to see into holes in the rocks/reef; so its always a good idea to carry a torch even on a day dive.