The structures are gradually being installed on the east and west banks of the river near the Old Toll Bridge.
Artists Jane Fordham and David Parfitt have almost finished laying the mosaic foundation on the east bank upon which a bench will be placed.
The bench will look towards 11 arches, which have all been individually crafted after consultation with the relatives of those who died.
The arches, currently being finished at Jane and David’s Portslade studio, will eventually reflect the likes and loves of the individual victims, with metallic sculptures of cats and basketball nets among the feature which will take shape around them.
Martin Randall, director for the economy at Adur and Worthing councils’, and Lara Southam, the councils’ project manager, were recently given a tour of the project as it nears completion.
Mr Randall said: “I was really impressed with what I saw. Jane and David are creating a memorial which is moving and will stand the test of time as an inspirational piece of work.
“The way they have involved the relatives in the work so that it reflects the personalities of those who lost their lives is awe-inspiring.”
Across the river on the west side an installation will support a series of 11 points of light which will be visible through the arches.
Jane and David hope to have the entire memorial, which has been supported by Adur District Council and local business donations, installed within the next few months.
Eleven men died when a Hawker Hunter crashed during a display on August 22, 2015.
They were: Maurice Abrahams, 76, of Brighton; Dylan Archer, 42, of Brighton; Anthony Brightwell, 53, of Hove; Matthew Grimstone, 23, of Brighton; Matthew Jones, 24, of Littlehampton; James Graham Mallinson, 72, of Newick; Daniele Polito, 23, of Goring; Mark Reeves, 53, of Seaford; Jacob Schilt, 23, of Brighton; Richard Smith, 26, of Hove and Mark Trussler, 54, of Worthing.
The pilot Andrew Hill, 53, of Standon Road, Buntingford, Hertfordshire, has been charged with 11 counts of manslaughter by gross negligence and one count of endangering an aircraft, contrary to Article 137 of the Air Navigation Order 2009.
A date for his trial has been set for January 14. It is expected to last at least five weeks.