In the age of information, who's thinking?

I was, throughout my tour of largely similar fish, doing my best to read the little plaques next to each tank, which told me and other curious visitors the name, feeding habitats and musical tastes of whatever was diving, swimming or floating upside-down inside. About halfway through this fabricated subterranean labyrinth, my conscious mind suddenly latched onto an oddity. I realized that underneath the descriptions of the various natant ichthyoids there was a translation of what I presumed to be the same information in Braille. For a while this seemed quite natural, and then I caught myself wondering: on average, how many blind people a year visit the London Aquarium? Now I don't want to sound insensitive, but I imagine the number must be negligible.
I would welcome any answers from blind people to a couple of questions that have been bugging me since. Firstly, how do you know where the Braille sign is located? This must be relatively straightforward in such things as lifts, but what about in an alien environment? If alone in a train toilet, how does one find Braille instructions for the use of obscured or unusual soap dispensers or toilet flushers? That sounds like an unpleasant and even unhygienic search to be undertaking while bumping around somewhere near Didcot Parkway. My second concern, clearly, is if a blind visitor found the Braille sign in the Aquarium, of what earthly use would it be? Aside from possible fleeting strokes of passing stingray in the 'touching pool', the London Aquarium seems to be an experience ill suited to visitors with severe visual challenges. It occurred to me that the Braille signs, if located, would at best provide the blind visitor with no more to take with him from his afternoon than a list of fish.
Derren Brown