A beach is a place where land meets water and, often, people. It may be sandy or rocky, warm or cold, covered with vegetation or devoid of it, crowded with tourists or deserted. Beaches are a familiar environment for most people, but most don’t know that they are dynamic, constantly changing ecosystems. The term “beach” usually refers to the area of a shoreline above water, but it can also describe any place where sediment and debris is washed up by waves or wind. Beach sand is typically composed of geologically-derived fine grains, such as quartz or feldspars, or biologically-derived coarse grains from the break down of marine organisms and coral skeletons. Beach slopes are often steep, but they can also be gentle or almost flat.
The main way that beaches are created, changed, and destroyed is by sediment drift and wave action. Tides and ocean currents deposit or take away sand, seaweed, shells, even whole marine animals like crabs, and may move it a few meters or hundreds of kilometers. Beaches are also altered by human activities, which can add materials or destroy them.
Geologically-derived sand is formed by the weathering of rocks, while biologically-derived sand is deposited by the breakdown of marine plants and animals and by eroded clam and oyster shells. Both kinds of sand can occur on beaches, and most beaches have a mix.
Fine-grained sand, such as silt and clay, are seldom found on beaches, since waves quickly suspend these particles and carry them either landward into the marshes and dunes behind barrier islands or seaward into deeper water where they form submarine bars. In addition, the turbulence caused by waves breaking off a beach excavates troughs and deposits sand at the trough’s offshore flank. Sand suspended in backwash and rip currents adds to these troughs and forms beaches.
The crests of surf, or waves that break just over the sandline, are another common feature of beaches. These waves may be calm and peaceful or fierce and turbulent, forming waves that attract surfers from around the world.
In many jurisdictions, public access to beaches is provided by law. Owners of abutting land can limit beach access, however, and signs are sometimes posted to show where private ownership ends. Beaches are also frequently used for recreational activity, such as swimming and surfing. These activities require specialized equipment, including surfboards. Beginners should consider purchasing a surfboard that has an appropriate size and shape for their height, body weight, and experience level. This will help them to feel comfortable on the board and avoid any injuries. It’s important for beginners to wear lifeguard-approved clothing, including a wetsuit, while they are learning how to surf. It’s also a good idea for newbies to surf under the supervision of an experienced surfer until they have developed their skills. This can prevent injury or drowning. It’s also recommended that surfboarders wear a leash to avoid losing the board in rough conditions.