The slip and breakwater at St Catherine are being surveyed to determine the level of repairs needed to secure the structure.
Sections of the slip were damaged during Storm Ciarán, leaving large cracks and heavy erosion of the stonework at the lower end.
The survey will be completed using drones, ground penetrating radar and multi channel analysis of surface waves to assess the full extent of the damage.
Access to parking spaces, the breakwater and slipway will be restricted for a time while large pieces of equipment are being used.
Ports of Jersey says the work is essential before being able to plan any repairs, which will be undertaken once the results have been analysed.