2. Rock Armour /Break water Rip Rap- large boulders on the beach absorb wave energy and break the power of the waves- although movement of the boulders is expensive this can be a much cheaper method than some other solutions- the boulders can however be undermined easily by waves washing away sand and shingle beneath them. They also can be quite ugly, changing the appearance of a coastline.
3. Gabions Gabions- these cages of boulders are built into cliff faces to protect the cliff from the force of the waves;- they are cheaper than sea walls and can be very effective where severe erosion is a problem- they are however visually intrusive
4. Groynes Groynes- these structures (usually either wooden or steel) are designed to stop long shore drift and therefore act to build up and anchor beach material, protecting the base of cliffs.- they are effective at reducing erosion in the area they are constructed in by causing significant build up of beach material- groynes may however starve areas further down the coast of material by stopping long shore drift, resulting in an increase in erosion in these areas
5. Revetments Revetments - these wooden structures break the force of waves and beach material builds up behind them- they are cheap and effective at breaking waves- as well as being visually intrusive however they do need replacing more frequently than most other defence methods.
6. Sea Wall Re-Curved Sea Wall- concrete wall which is curved on the underside to deflect the power of the waves- these can be very expensive (up to £1-2 million per km) and the deflected waves can scour material at the base of the wall causing them to become undermined- these are however a very effective means of preventing erosion and they reflect rather than absorb wave energy.
