I also dive the hosecollar BC very often. I also own the latest styles of wings like the Mach V. The hosecollar is the lowest drag BC even compared to the Mach V. They fit well and provide positive airway positioning when inflated. They generally have a nice pocket on the front that is very useful and also often have emergency CO2 inflation which can be disabled simply if you wish (and I do). For divers who have learned to dive sans BC then using a horsecollar is very simple and efficient. You dive the horsecollar much like with no BC and by this I mean you need to set weight requirments and trim very close to optimum and as little as possbile weight. This allows the horsecollar to trim well and essentially is along for the ride with very little air put in it. If your overweighted and then need to as a result pump a bunch of air into the BC (as is common today---over weighting--grossly!!!!!) then the horsecollar BC and hip weight belt will cause the diver to rotate into a head high and feet low position--especially at rest and this is not good for efficiency. However--if properly weighted the horsecollar will require little air and therefore will trim very nicely horozontal.
Another advantage for some specialty aspects of diving or rescue is that they are independent of the other gear and dive gear can be doffed and the horsecollar retained---you put it on first of course.
Here is a pic of the best horecollar ever made, the Dacor SeaChute twin bladder. It provides solid horozontal trim, is very sleek and efficient in the water and notice the nice pocket.
I also have a new SeaTec horsecollar, it is sleek and it is BLACK (lol) and it is very efficient in the water. I enjoy using it for beach type diving. I dove it last Monday on the Destin Jetty (March 26).
In someways the horsecollar is superior to a wing--certainly for emergency head up flotation it excells. The drag question will be argued until somebody puts them in a hydro tunnel but the Dacor and Seatec compare very favorable to my Mach V OxyCheq and I feel they have lower drag if only slightly.
Think of the horsecollar, like the wing, as a minimalist approach to diving. Consider the horsecollar as nothing more than a chest mounted donut wing.
Some divers,in fact most, dive only one setup or the same set up but with single or double tanks. I dive three different basic setups or rigs if you prefer.
1) No BC, sleekest and most neutral. Excellent trim and super minimal. Simple backplate or SeaHunt harness.
2) Horsecollar BC, simple backplate or SeaHunt type harness
3) Hog(ish) rig with wing and backplate
Each has their place and purpose, I almost feel badly for those who fixate upon only one rig, they are missing out. Versatility is a good thing and the horsecollar is very versatile.
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