Armoring involves building revetments, seawalls, detached breakwaters, groins, etc. Such structures include seawalls, gabions, breakwaters, groynes and tetrapods. The construction of seawalls and breakwaters reduced the power of waves at some locations. It is often found on man-made structures such as breakwaters and jetties. In shallow water, revetment breakwaters are usually relatively inexpensive. Connie also damaged fishing piers, breakwaters, and housing shingles. They are used to protect harbour walls, breakwaters and shore earthworks. A navy salvage crew eventually managed to remove the ship from the seawall/breakwaters. Staithes has a sheltered harbour, bounded by high cliffs and two long breakwaters. Artificial harbours can be created with the help of breakwaters. The harbour is formed by two converging breakwaters. Restoring reefs is significantly cheaper than building artificial breakwaters in tropical environments. They built walls underwater and constructed solid breakwaters. Rubble mound breakwaters use structural voids to dissipate the wave energy. The harbour was made by the building of stone breakwaters between 1848 and 1905.