These two skydivers were having a little too much fun and decided to keep the party going below their usual deployment altitude. The first jumper had a canopy over his head by 1,600 feet (approx. 500 meters), while the other jumper skimmed passed the opening parachute in freefall and opened by 800 feet (appox. 250 meters). Keep in mind this is GoPro POV, so "objects are closer than they appear" in this video.
Altitude awareness will keep you alive, so it doesn't hurt to use an audible (or two) as a reminder of your altitude, pay attention to your altimeter when you consciously look at it, know your hard deck and practice your emergency procedures.
As skydivers, we can't afford to lose track of altitude in our sport — gravity will always win.
Live and learn.