If we take down lights on a day dive (only if we aren't carrying the camera or video rigs) then we just take one light.
On night dives we have tank lights and one primary light each. One of us carries a backup light, small one only. I HATE it when people do night dives with those HUGE lights! Its like an aircraft carrier coming in for a landing. I want to see the fishlife out walking around, not running for their lives for fear of getting burned to death by the monster SUN attacking them underwater.
