Stone groynes Wooden groynes and Sea Walls Hope this helped :')
Groynes, sea walls and rip-raps
a single groyne cost about £5,000 per metre http://www.mjanderson.chislehurst.btinternet.co.uk/coastseadefence.htm this is where find more of the cost of sea defences :D
Groynes are used for blowing bubbles .
Wooden groynes work belkhebra
1. Sea walls 2.Rip-rap 3.Revetments 4. Groynes 5.Gabions
Groynes, columns of boulders and sea walls are the most popular ones. sea walls are the most expensive, costing about 700,000 pounds per metre!
Groynes prevent or slow down erosion.
The sea defences consist of Rip Rap(rock armour); sea wall; revetments; Gabions; holes in pavement; Groynes; offshore breakwater and beach seeding.
They need groynes to prevent te sand going in land slides
They are afraid to go far by sea because they are scared that maybe the go somewhere they don't know(nowhere) and they are afraid of the weather(hurricane, storm etc.) and disease(scurvy).
Don't let people build on barrier islands.