I'm aware that I can use / followed by a regex to search something. And I can use ? to search backwards. And I can use n and N to repeat the search forward and backward.
There are also two nice shortcuts: * or # will search for the word under the cursor (forward/backward). That's very useful! (there are also g* and g# variants)
But... Once I've selected text using visual mode (v), how can I ask Vim to search for exactly that text? A quick look at :help did not... huh... help me.