If a surfer falls while riding a wave, the wave tosses and tumbles the surfer around, often in a downwards direction. At reef breaks and beach breaks, surfers have been seriously injured and even killed, because of a violent collision with the sea bed, the water above which can sometimes be very shallow, especially at beach breaks or reef breaks during low tide. Cyclops, Western Australia, for example, is one of the biggest and thickest reef breaks in the world, with waves measuring up to high, but the reef below is only about below the surface of the water. Microorganisms A January 2018 study by the University of Exeter called the "Beach Bum Survey" found surfers and bodyboarders to be three times as likely as non-surfers to harbor antibiotic-resistant E. coli and four times as likely to harbor other bacteria capable of easily becoming antibiotic resistant. The researchers attributed this to the fact that surfers swallow roughly ten times as much seawater as swimmers. Ear damage Surfers sometimes use ear protection such as ear plugs to avoid surfer's ear, inflammation of the ear or other damage. Surfer's ear is where the bone near the ear canal grows after repeated exposure to cold water, making the ear canal narrower. The narrowed canal makes it harder for water to drain from the ear. This can result in pain, infection and sometimes ringing of the ear. Ear plugs designed for surfers, swimmers and other water athletes are primarily made to keep water out of the ear, thereby letting a protective pocket of air stay inside the ear canal. They can also block cold air, dirt and bacteria. Many designs are made to let sound through, and either float and/or have a leash in case the plug accidentally gets bumped out. Surf Rash Surf rash appears in many different ways on the skin, commonly as a painful red bumpy patch located on the surfer's chest or inner legs. A rash guard will lessen the incidence of surf rash caused by abrasion or sunburn. Healing ointments such as petroleum jelly can be used to treat irritated skin. Spinal cord Surfer's myelopathy is a rare spinal cord injury causing paralysis of the lower extremities, caused by hyperextension of the back. This is due to one of the main blood vessels of the spine becoming kinked, depriving the spinal cord of oxygen. In some cases the paralysis