Night motor racing uplink, we used to hover at 2500-3000ft, but there wasn't a lot of lighting apart from the track directly underneath, and Melbourne Airport 5 miles away! The B206 would drift around a little bit, but the worst was to allow any backwards drift and subsequent nose up pitch. Time in the hover varied from 15 to 45 minutes, depending on the race and the number of bingles
Wearing bi focals and glancing down wasn't much cop, either
I guess the most important thing was/is the same as hovering overwater: keep your scan and visual reference point(s) well away from the helicopter, and put a lot of reference out toward the horizon.