Snorkels are used for surface swimming and allow divers to breathe while floating face down in the water. They consist of a tube with a mouthpiece and often feature a purge valve to clear water. Snorkels are simple yet effective for surface snorkeling or when diving in shallow waters. They come in various designs, including those with flexible tubes and splash guards to prevent water entry. Proper use and maintenance are essential to ensure the snorkel remains free from blockages and performs effectively.