What are some experiences and results with this bit? My mare went really well in a dee ring Waterford in her hunter bridle. Now that we have been focusing on Dressage we've been in a HS French link loose ring without nearly the better results. It seems oddly enough to excite her.
Others on here with more experience should chime in about what bits might work for a horse that goes well in a Waterford.
If you're really at loose ends, ask to borrow as many bits as you can from your dressage friends! Most of us have way more bits than we have horses! Just be sure that the mouthpiece is the right size for your horse.
HS makes several double-jointed loose ring bits. After a lot of trial and error, I discovered that my little mare likes the very basic KK mouthpiece loose ring, with the bridle cheeks adjusted to hold it pretty high in her mouth.
I tried a waterford for a few rides last winter, as a potential bit for jumping (I event) and ended up not liking it, as it was way too much bit for my horse. I took two lessons in it, and was told NOT to try to really do any "dressage" in it when warming up, because, essentially, you can't ask the horse to push forward onto a bit that collapses every time they go onto it. So not only not legal for dressage, rather counter productive.
Your horse doesn't need to be in a loose ring for dressage. If she was going nicely in a waterford dee before, have you tried her in a frenchlink dee? I know we messed around with bits for jumping all last winter with mine (who as a mare, most decidedly Has An Opinion about whether something works or not, as I'm sure you know!) and what we eventually realized was that it wasn't so much the mouthpiece as the stability of the bit--she hated hated hated the loosering moving around, and is not happily going in a (french link) baucher for dressage and a fullcheeck for jumping/xc. Don't discount the difference a cheekpiece can make.
I will second quietann's suggestion of borrowing bits; barnmates were always willing to share recommendations on what had worked for them, and quite happily offer up bits to try, as well as my trainer sharing a few with me.
But also be aware that you're now asking the horse to come onto a fixed bit with steady contact, something that she was unable to do with a waterford before.
As JenEM points out, the waterford isn't made for the horse to take contact with. So your horse is probably trained to avoid contact and in a "false" frame from it.
What does your mare do exactly with the loose-ring? Is she hollow? Neck uo in the air? Resisting and hard in the mouth? Pulling? twisted/crooked in her body?
How is your mare's mouth? Maybe she liked the waterford because it wasn't taking much space in her mouth and not touching the roof palate. Maybe try something that sits lower in her mouth. Have you tried to put the loose ring a bit higher in her mouth? Sometime people puts them too low so it doesn't sit at the right place. Don't be afraid to try it for a few rides and see if she likes it better.
I actually took dressage lessons with an upper level trainer with my gelding in a loose ring waterford. He was big, strong, stubborn, and had learned that leaning/pullying/barreling would get him his way and the retraining process was a trial.
He LOVED the waterford. He played with the balls and was much lighter and we made good progress with it until I was able to switch him to a dressage legal snaffle.
I used it again on a mare that was afraid of contact, she seemed to like the soft rope like feel of it in her mouth and also eventually switched to a regular snaffle.
Similar to some of the above posters, I had my mare in a loose ring waterford for a while. We were doing a fair amount of jumping/hacking/XC, and she could get quite strong, but the waterford was a good compromise (previous trainer had her in a three ring elevator; worked ok for jumping but mare threw a fit when I tried to do any flatwork in it!). She now goes in a plain old loose ring snaffle, now that I am back with my original coach and am riding better. But I wouldn't hesitate to switch back when we hopefully get to do more XC next summer, IF she needs it. Definitely see if you can borrow bits from friends and barn mates, until you find something your horse tells you she likes!
A loose-ring Waterford is the "tune up" bit for my pony. Normally he goes in a pain D-ring snaffle. He tends to get heavy and really lean on my hand at times, and occasionally I just can't get him "in gear" and carrying himself with the snaffle, so we go to the Waterford for a ride or two. It does a nice job of backing him off my and getting him light so we can go back to the snaffle.
Proud member of the "I'm In My 20's and Hope to Be a Good Rider Someday" clique