Protesters say closing the lighthouse that inspired novelist Virginia's Woolf's best known work would put lives at risk.
There is a light that should not go out, say protesters
Lighthouse authority Trinity House plans to switch off Godrevy light on the edge of St Ives Bay by 2010.
The octagonal white tower marks a reef called the Stones and has been in service since 1859.
Woolf's novel To The Lighthouse drew on her memories of childhood holidays in St Ives.
On Wednesday Cornwall County Council met officials from Trinity House.
Council leader David Whalley said many fishermen and small craft owners could not afford to install their own navigation systems.
"I am very concerned that relying on electronics alone could lead to lives being lost," he said.
Trinity House spokesman Emma Skingley, said: "We are looking at current and future predicted needs of mariners.
"Godrevy is one of the ones that is proposed to be discontinued, but if there is feedback saying we need the lighthouse, that will be taken into account."