All snorkels are of similar dimensions to allow both ease of breathing and clearing. Some snorkels are now fitted with a purge valve to allow water to drain from the bottom of the tube rather than be ejected by blowing. However the seals of such snorkels can leak if grit or sand fouls the outlet. Sealing the top of the tube with your hand and forcefully clearing the one way seal, thus flushing out any debris, may clear this. A variety of ingenious methods have been devised to attach the snorkel to the mask strap including a sleeve or clip or quick-release attachments.
Snorkels are available in ranges of colours to match the mask.
And so to our means of propulsion - the fins. There are two main types of fin, shoe fin and open heel fin. The shoe or pool fin is ideal for the beginner, being smaller and offering less surface resistance in the water and is consequently less tiring on untrained leg muscles. Both types of fin are constructed of similar materials, rubber foot sockets and plastic blades. The open heel fin however is larger, heavier and more robustly constructed, being designed to accept a dry or wet boot and to be used in open water.