How fast do sharks swim? When just cruising sharks can move at a speed of 5 miles per hour, but when they are pursuing a prey they can swim at a speed of 12 miles per hours. Sharks are also capable of sudden speed bursts when needed. They can increase their speed at 30 miles per hour. Do you know that their teeth are replaced continuously throughout their lifetime? It is estimated that a shark can lose around 30,000 teeth throughout its life. That's a lot of teeth! More fascinating information and amazing pictures of sharks are featured in this book especially made for young learners.