Snorkels are a simple but essential tool for both snorkeling and scuba diving so you can see into the water and breathe at the same time. There are two main designs of snorkels. The simplest snorkel is a fixed tub with a U-bend and mouthpiece often preferred by freedivers. Modern snorkels have a one-way mushroom valve at the base of the mouthpiece that acts as a purge/drain valve. Some snorkels also have a splash guard at the top of the snorkel to massively reduce water from getting in your snorkel. But don’t worry, if it does, simply exhale sharply and this will clear your snorkel.