A compactly stowable marine loading arm especially suitable for mounting on he deck of relatively small or coaster-type marine tankers to facilitate transfer of fluids, and especially petroleum products such as bunker fuel, from the tankers to other ships, particularly container-carriers. The loading arm comprises an inboard arm section mounted on a riser for pivotal movement about horizontal and vertical axes, and an outboard arm section joined to the inboard section for pivotal movement about two additional horizontal axes and another vertical axis. The loading arm is arranged to be stowed in a horizontal attitude with the outboard section extending back toward the riser and overlying the inboard section. When the arm is used, the outboard section is pivoted about the vertical axis at its juncture with the inboard section until it extends forward from the inboard section in the desired functional direction. A counterweight carried by the inboard section provides a counterbalancing force for the arm about the riser's horizontal axis, and a sheave and cable system maintains the outboard section's elevational attitude, i.e., with respect to the vertical, as the inboard section is raised or lowered, this attitude being variable by a suitably mounted hydraulic cylinder or equivalent means.