The speed of waves flowing in from the open ocean can range from 8 to 10 miles per hour for lesser waves to up to 35 miles per hour for a tow-in-sized wave. To catch the wave, you must paddle in front of it quickly enough that the wave does not pass directly beneath you. The faster the wave, the further ahead you need to be to avoid being overtaken by its face. The average human swims about as fast as a surface water wave, which is why long-distance swimmers have been called "surfers". A man who could swim faster than a wave would be a force to be reckoned with and might be able to save himself from certain death under some circumstances. For example, if he were riding a giant wave he could pop out of the way in time to avoid being crushed by the collapsing foam left behind when the wave breaks. The fastest animal on earth is the shark. Some species can reach speeds of 50 miles per hour or more for short distances. This speed may not sound very great until you remember that a shark's body mass is measured in tons and it takes much more energy to move a heavy object through air than through water. For example, a shark of typical size will need to eat about 15% of its weight in food every day to stay alive. That's like eating four large bananas or three sheep. Sharks are best known for their teeth.