Abstract: This invention concerns a semi-submersible marine platform comprising an above water deck, a support structure extending downwardly from the deck into the water and supporting the deck on pods providing buoyancy for the platform, and stabilizer legs spaced around the support structure and outrigged underwater thereby or therefrom, each stabilizer leg preferably being free to pivot under environmental forces about an underwater universal pivot and extending upwardly therefrom to project substantially above mean water level and provide a cut water plane area for imparting a righting moment against environmental forces acting on the platform.