Work to move thousands of boulders on the sea bed off the south coast of England is getting under way to enable a 116-turbine wind farm to be built.
The Rampion wind farm, between Peacehaven and Worthing, is the first to be located off the south coast.
Energy firm E.On said the seabed would be cleared along the cable route and around each of the turbine positions.
Work is also beginning onshore on the first of 12 cabling stages to the south of Upper Brighton Road, Worthing.
'Replicate the seabed' E.On development manager Chris Tomlinson said: "Assessment of the number of boulders is still under way but is likely to be in the thousands and up to six vessels will be on site to undertake the work over the next many months.
"Great efforts will be made to replicate the seabed as it is now and all boulders moved will be weighed and the new position recorded."
Installation of the turbine foundations will begin in January.
The £1.3bn wind farm eight miles off the Sussex coast will be visible from the shore and the South Downs National Park.
Onshore, access points will be constructed along the cable route.
This will be followed by trenching works to lay the ducting for the cables which will cross the national park and link to a substation in Twineham.
The wind farm could produce enough electricity for about 300,000 homes.
During the three-year offshore construction period 250 to 300 jobs will be created, with 65 permanent energy jobs once it is fully operational with a base at Newhaven Port.