An articulating strut capable of assuming an extended in-line and a folded configuration with rigid cylindrical tubing having proximate ends configured to fixably receive an offset hinged insert that provides for folding and unfolding of said strut. When fully unfolded the strut acts as a single rigid structural support member held in the locked position by a bi-directional slidable locking sleeve. The hinged insert has full faced load bearing surfaces which together with offset hinge pins tends to direct the strut members under compression to assume an over-center locked position. Such struts have particular application as bimini or dodger marine coverings that fold or become taut without tensioning straps or supporting tension in the covering material itself.