NOVELTY - A hollow tubular ballasting element (290) integral to lightweight dual turbine shroud (260), has their ends sealed by end caps. Inner wall of element and end caps define a watertight void in which a reversible polarity actuator is attached. The actuator rotates a shaft for moving ballast in void towards end cap. Movement of ballast changes center of gravity of dual turbine unit, changing its attitude.    USE - For adjustable deployment in path of water flow for electrical power generation.    ADVANTAGE - Dual turbine arrangement effectively counteracts rotational counter torque of individual turbines, thereby enabling stable deployment of unit without requiring rigid stabilizing structures.    DETAILED DESCRIPTION - Dual turbine unit (210) comprises turbines (220,240) having respective turbine runner assemblies (222,244). The assemblies comprise several turbine blades (226,246), respective turbine shafts in general axial alignment with path of water flow. Turbine hubs (224,242) fixedly mounts respective turbine blades radially outwards with respect to axial alignment of respective turbine shafts. Modular turbine generators are coupled to respective turbine shafts through a speed increaser for converting kinetic energy into electrical energy. A lightweight dual turbine shroud (260) made of material selected from a group of materials including thermoplastics and fiber glass, captures the turbines. The shroud has a front edge (262) facing oncoming water flow, and rear edge (264) proximate to a point of water discharge from dual turbine unit. An augmentor ring (266) proximate to and integral with rear edge of shroud, extends radially outward with respect to axial alignment of respective turbine shafts.    DESCRIPTION OF DRAWING(S) - The figure shows the dual hydro turbine unit.    Dual turbine unit (210)    Turbines (220,240)    Turbine runner assemblies (222,244)    Turbine blades (226,246)    Lightweight dual turbine shroud (260)    Front edge of shroud (262)    Rear edge of shroud (264)    Augmentor ring (266)    Hollow tubular ballasting element (290)