There are many differences between these two disciplines than timed (jumpers) vs. untimed (hunters).
Hunters:
We all have noticed that A-circuit show hunters are a bit snooty, but I have to say their sport almost requires them to be just so! I think it's quite an accomplishment to score well in the hunter ring. This discipline focuses on sweepy, ground-covering strides, the expression and temperament of the horse and his/her form over the fences. It can be extremely subjective. Imagine one of those paintings above the mantel of a fox hunt happening someplace in Great Britain. Those horses are jumping over small stone fences, fallen logs, perhaps a hedge or two--all while looking completely at peace in their environment. They have to remain calm, steady and be fit enough for a long day of hunting. This is the inspiration behind the hunter discipline.
All jumps in a true hunter ring are naturalistic in color (green, white or bare wooden). The courses are not as technical and the fences are not as high as jumper courses with tight turns or rollbacks, and--of course--you're not timed.
The horse is judged on:
1) How close the horse can get their feet to their ears over the fence
2) How consistent the horse is throughout the course, with respect to speed and tempo
3) How simple the horse looks to ride (the goal is that anybody’s grandmother could ride the horse)
4) Confirmation of the horse with respect to its age.
So basically, the most beautiful horse with the most effortless seeming round (without knocking any rails) will be the winner. No pressure there!
Learn all you'd ever want to know about how the rider is judged (and more) in the USEF Hunter Seat Equitation Manual.
Jumpers:
Alrighty. Jumpers. Higher jumps, tighter turns--a more technical ride indeed. This discipline is more of an equitation challenge for the rider. It's not as pretty but these horses and riders have to be super efficient while riding against the clock.
It's easier said than done, but to be a successful jumper you can't be afraid to go a bit faster--gallop! Well, not all the time. But the top jumpers go in with their feisty horses all strung out and galloping, then they collect the horse onto the haunches before the jump. There is no "auto pilot" for jumpers. They need to do more decision making!
In an ideal world training for hunters, jumpers or any discipline should be similar: striving for balance and an ample amount of forward impulsion while maintaining good communication with your horse. The best hunters, jumpers, eventers, reiners, dressage riders, etc. all have this in common. So if you as a rider can keep this in mind, it will set you up to have an effective and safe seat.
