Are reefs waterproof?

The idea of reefs being waterproof seems rather self-evident, doesn't it? After all, reefs are naturally occurring formations made up of coral, rocks, and other materials that are constantly submerged in water. But let's delve a bit deeper into this question. Could reefs somehow lose their ability to withstand water? Could there be circumstances where they're no longer 'waterproof'? For instance, if a reef were to undergo significant erosion or damage from human activities, could it become less resilient to water? Or are reefs inherently designed to withstand the constant assault of waves and currents, ensuring their waterproof nature remains intact? Let's explore these possibilities and uncover the truth behind the question, 'Are reefs waterproof?'