Kangaroo Island residents marked out a message to Norwegian oil company Equinor on Vivonne Bay beach on Saturday.
That message was "KI2GOOD2SPOIL" and it was part of the Bight Back series of actions around Australia.
More than 100 people attended the action at Vivonne Bay and lined up next to the message written on the beach and then highlighted with seaweed.
Several people also paddled out into the surf, and a drone was flown overhead to capture footage.
Simultaneous protests against oil drilling plans in the Great Australian Bight were held at Ceduna, Streaky Bay and Port Lincoln over the weekend.
Organising Saturday's KI action was Linda Irwin-Oak, who co-runs the Oil Free Seas - Australia group that was founded by Sharon Zealand, back when oil company BP first indicated it was interested in exploring the Bight.
"I really love this island community. Met some amazing beautiful people today, was so overwhelmed by how many of you came at such short notice to fight for the Bight. Thank-you once again," she said.
"Go home Equinor" was the catch cry of the day and a drone was flown over the beach to capture footage.
Kangaroo Island/Victor Harbor Dolphin Watch founder Tony Bartram also took to the microphone, urging everyone to make a submission to the regulator on Equinor's Stromlo-1 exploration drilling program.
Submissions to National Offshore Petroleum Safety and Environmental Management Authority must be made by March 20 - click here to make a comment
KI resident Craig Smart performed a song he just wrote called "Oil Slick Coast" with the words; "Now that the beaches are black, this is just another nowhere track".