Sidemount teams often don't even bother with a long nose. Each diver manages his gas so that he can safely exit on either tank. In addition, it's possible to switch a working regulator to the other tank on a breath hold or feather the valve on the tank with the problem. Obviously, if you're diving as a mixed SM/BM team you will have a long hose for your BM partner.
So, I'm just getting my gear together and learning SM, but you can switch regulators underwater? I thought the 1st stage would flood? (which is why we have dust caps and make sure they are seated before we rinse them?
I'm sure I'll be corrected, thanks in advance.