Middles is a shallow, bowly, close-to-shore, brilliant, blue right tube. Take off behind the crease, stay high, keep your eyes open, and you're in for one of Puerto Rico's best and most coveted views. The reef itself is an irregular coral/rock shelf that juts out from the golden sand beach; any kind of N swell hits the thing straight on, and depending on direction, the wave can bend into a short intense bowl or a longer, slightly less-intense wall. The rock at the east end of the beach blocks the trades for a few moments -- and can build up a nice little sandbar in its lee. Even when it's under head-high it can be shifty, steep and fast.
Source: Middles Surf Guide