Turbines planned for 10 miles off the Angus coast would be five times the size of the 200-year-old Bell Rock lighthouse, say Angus Council's planners.
The council is due to submit comments on the development to Marine Scotland and says the impact of the planned 213-turbine windfarm would be "significant and unacceptable" on the seascape.
The council will now ask Marine Scotland, which decides on offshore windfarms on behalf of the Scottish ministers, to look deeper into the effects of the 450 megawatt windfarm.
Bell Rock Lighthouse expert David Taylor said: "The view of the lighthouse will be ruined. It's really a despoiling act to build this windfarm."
In the report, Angus Council planning chief Vivien Smith said: "The Bell Rock lighthouse is the only tall structure in the seaward view and, apart from passing ships, the only light source at night on an otherwise dark horizon. It is evident that the proposed development will have an impact on the seascape."
With other planned turbine developments she says "significant cumulative seascape effect" is possible.
Inch Cape Offshore Limited (ICOL) won development rights in 2011 for the site on the Bell Rock or Inchcape reef. Historic Scotland and the Scottish Environment Protection Agency have not objected to the proposal. Scottish Natural Heritage has yet to respond.
The council says a seascape assessment from the developers "has a number of shortcomings" and does not reference the lighthouse.