Hunt Seat EQ-pattern class (the judge picks the pattern) and is judged on you-your position, seat, and abilitly to control the horse. same saddle as english pleasure. at the end of the pattern (when everyone's done) you do some rail work for about two minutes. sometimes you have to drop your stirrups in higher level shows during rail work (judge's decision). you need to sit up, look forward, smile, heels down, shoulders back, hands still (hold them like you're holding a tray, at a 90 degree angle), and shoulders square. your horse will have to do simple/flying lead changes, back up, trasition gaits nicely, do pivots and pull turns. depends on the pattern. no jumps. your reins will be a bit tighter b/c you need control over the horse to do the required acts. make sure to not rush through your pattern. this is a formula for disaster. don't take toooo long or else the judge will mark you down some.
English Pleasure (Hunter Under Saddle)-class that requires you to walk, trot, canter, and back up. it's not like hunter hack at all. it's a flat class. you need to sit back more in this class (but not a whole lot more) and your horse's head needs to be level with it's withers. the flater the knee, the longer the stride, and the elegance of the ride the better. same english saddle as in hunt seat eq. consistency is key.
here's a pic of it-http://www.talkoftheparty.net/sitebuilder/images/And_rightly_So-395x317.jpg
http://geneparkerfarms.com/images/skysblueboy.jpg
(the trot ^)
Edit: haha ya, me neither. there's absolutely no jumps at all...