They are called fringing reefs. They grow directly from shore and form borders along the shoreline.
When a fringing reef continues to grow upward from a volcanic island that has sunk entirely below the sea level, an atoll is formed. Atolls are usually circular or oval in shape, with an open lagoon in the center.
The fringing reef is the most common type of coral reef. They however tend to be very sensitive to human induced pollution in the water and are easily destroyed by such.
Answer:
Fishing I write the answer
On the medieval world-maps it was represented only the part of the world known as the 'old world', which is consisted of Europe, Asia and Africa. Before the big discoveries, people living in this continents had knowledge only of this part of the world, while South and North America, Australia and Antarctica where still unknown to them, thus they are missing in the world-maps of this period.
The way the moon effects the tides on earth is the gravity between the earth and moon and I would go into more detail but that would take all day
That would be the Himalayas and have the highest mountain range in the world.