1. Stopping waves breaking the rock sea wall A seawall (also written as sea wall) is a form of hard and strong coastal defence constructed on the inland part of a coast to reduce the effects of strong waves. In the UK, sea wall also refers to an earthen bank used to create a polder, or a dike. The term is also sometimes used for walls used to make artificial harbours and port facilities. Seawalls may be constructed from a variety of materials: most commonly, reinforced concrete, boulders, steel, or gabions. Additional seawall construction materials may include vinyl, wood, aluminium, fibreglass composite and with large biodegrable sandbags made of jute and coir. Seawalls can be expensive to build, today costing between $4000 to $7000 per metre (£2000 - £5000 per metre).Modern concrete seawalls tend to be curved to reflect the wave energy back out to sea. Poor designs require constant maintenance as waves erode the base of the seawall.

2. groynes A groyne (groin in the United States) is a rigid hydraulic structure built from an ocean shore (in coastal engineering) or from a bank (in rivers) that interrupts water flow and limits the movement of sediment. In the ocean, groynes create beaches, or avoid having them washed away by long shore drift. In a river, groynes prevent erosion and ice-jamming, which in turn aids navigation. Ocean groynes run generally perpendicular to the shore, extending from the upper foreshore or beach into the water. All of a groyne may be under water, in which case it is a submerged groyne. The areas between groups of groynes are groyne fields. Groynes are generally made of wood, concrete, or rock piles, and placed in groups. Groynes are common and require little maintenance. They are often used in tandem with seawalls. Groynes, however, may cause a shoreline to be perceived as unnatural and ugly.

3. revetments Revetments, or revêtiments (the original French word, meaning something to re-cloth or re-cover), have a variety of meanings in architecture, engineering and art history. In stream restoration, river engineering or coastal management, they are sloping structures placed on banks or cliffs in such a way as to absorb the energy of incoming water. In military engineering they are structures, again sloped, formed to secure an area from artillery, bombing, or stored explosives. In architecture they are a variety of structures, normally vertical, used to retain a wall, or sometimes just to decorate it. River or coastal revetments are usually built to preserve the existing uses of the shoreline and to protect the slope, as defence against erosion. For other meanings see below.

4. breakwater Offshore breakwaters, also called bulkheads, reduce the intensity of wave action in inshore waters and thereby reduce coastal erosion. They are constructed some distance away from the coast or built with one end linked to the coast. The breakwaters may be small structures, placed one to three hundred feet offshore in relatively shallow water, designed to protect a gently sloping beach. Breakwaters may be either fixed or floating: the choice depends on normal water depth and tidal range. Breakwater construction is usually parallel or perpendicular to the coast to maintain tranquillity condition in the port. Most of Breakwater construction depends upon wave approach and considering some other environmental parameters

5. gabions The most common civil engineering use of gabions is to stabilize shorelines or slopes against erosion. Other uses include retaining walls, temporary floodwalls, to filter silt from runoff, for small or temporary/permanent dams, river training, channel lining. They may be used to direct the force of a flow of flood water around a vulnerable structure. Gabions are also used as fish barriers on small streams. Gabion baskets have some advantages over loose riprap because of their modularity and ability to be stacked in various shapes; they are also resistant to being washed away by moving water. Gabions also have advantages over more rigid structures because they can conform to ground movement, dissipate energy from flowing water, and drain freely. Their strength and effectiveness may increase with time in some cases, as silt and vegetation fill the interstitial voids and reinforce the structure. They are sometimes used to keep stones which may fall from a cutting or cliff from endangering traffic on a thoroughfare. Gabions have also been used in building, as in the Dominus Winery in Napa Valley, California. The exterior is formed by modular wire mesh gabions containing locally quarried stone; this construction creates an environment of moderate temperatures within the building.