Protesters say the effects of gas extraction on Manx marine wildlife are "horrifying".
Extinction Rebellion Isle of Man will demonstrate against an ongoing survey to find gas in Manx waters.
It's taking place in an area of the seabed off Maughold Head.
Protester, Jordan McCarthy said gas extraction would also ruin the island's chances of achieving net zero by 2050.
He added: "I speak for the youth who will be around to see the worst of what's to come.
"We deserve the chance to grow up, to pursue careers, to raise families.
"We deserve to live our lives without facing disasters that were not our fault."
The demonstration will take place between 12:45 and 14:15 today.
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