I wouldn't hunt a horse where I thought every ride involved a significant risk of falling and motivated me to wear a vest every time. On the other hand, I don't think I'd join a hunt that specifically forbade a safety item if I wanted to wear one the first time I took a new horse out.
Tipperary made one for a while that looked kind of like a canary wool vest, but I'm presuming they were not a big seller.
One of the air vest companies currently has somebody wearing an air vest over the outside of their hunt coat in an ad.
I would think if one wore a a discretely colored,ie white or possibly black, underneath your jacket, no one would have a problem with it. It would of course, as all "proper attire" questions do, depend on your hunt.
I don't think anyone even notices "safety" helmets any longer, it's become pretty commonplace.
I'm sure we all know someone, who might wish they'd had one on under a jacket a time or two.
Usually all I bruise is my dignity.
There are many good riders who have fallen from many good horses, I don't personally think that wishing to lessen the impact is a bad thing. I'm not wearing a vest, but I'm looking (at my age) for a much shorter horse these days.
I also agree that I wouldn't want to be hunting if I felt like I needed it.
I think that is rather short sighted thing to say.
I doubt most people wear safety equipment because they feel like they need it (that they are in an unsafe situation). It is just a wise idea. Some of us bounce less than others when the world turns upside down, nothing wrong with taking some extra precautions if that is how things work for you.
Its not that they're not 'good' or 'accepted'. It's that they're designed to be worn on an 8-minute xcountry course, not a 3+ hour hunt.
I've broken bones with them, broken bones without.
You will be very uncomfortable with one on for that long.
That said, if it makes you happy, certainly wear it.
But I've seen plenty of people start out with them that throw in the towel once they 'realize' what a hunting day is actually like.
I have certainly considered it for my green bean's early outings as he's the only one of my horses athletic enough to slam-dunk me on a whim, but set the idea aside when I couldn't figure out how to keep my (not black or white) vest from showing under the traditional hunt duds. I've worn my Tipperary vest for long rides, and it's certainly no worse than bundling up with lots of layers in winter.
I don't belong to a hunt, but have capped (is that the word?) a few times with a couple of the local hunts. (Fantastic people -- would be so much fun to join but it's not practical right now...). No one looked down on me for wearing a vest (over my coat, no less) -- I did ask if it was permitted and the response was "absolutely!". As it turned out I was quite happy to have it on because I managed to get dumped right ON a fairly substantial log... . I'm by no means an expert on hunting, but you can always ask the hunt what they think.
ETA: Honestly, I don't find mine uncomfortable, so I've been ok even on long days. It's funny how the mind works -- I am so used to wearing one if I jump xc that I think I would feel nervous and probably ride like a big suck without it!!
Having lost an important member of their hunt in a fluke accident, my local hunt happily allows any and all safety equipment any member or guest wishes to wear. No need for permission ahead of time, members are treated like intelligent, responsible adults.
We have some members that wear protective vests under their coats. One is one of the old canary tipperary vests. It seems the vests have become less bulky over time, so are not as noticeable under a coat.
I agree with Hunter's Rest that three hours would be a long time to wear that vest. I know that when I finish a XC course, I am off the horse and that vest is off. Otherwise I am just baking and that's not even wearing a coat.
"I couldn't find my keys, so I put her in the trunk"
I wear a canary yellow Tipp when I do hunt at the suggestion of one of our masters. I got a great deal on it and have been called a few names for purchasing it used for $30 but have mostly received positive comments. I wear it under my jacket when it is cool but have worn it over a shirt when it was warmer.
I capped with another local hunt and wore it there too. I was really surprised to see several of there members wearing vests as well and had several others tell me what a good idea they thought it was. I don't get to ride in the hunt all that much and do belong to a very casual hunt, so I'm sure it is differs depending on your hunt.