  In this work we study magnetotransport properties in electronic double layers
of strongly correlated electron liquids. For sufficiently clean high-mobility
samples, the high-temperature regime of transport in these systems can be
described in pure hydrodynamic terms. We concentrate on the magnetic field
dependence of longitudinal drag effect mediated by the interlayer Coulomb
scattering and identify several mechanisms of transresistance which is caused
by viscous flows, magnetoplasmon resonance, and dissipative thermal fluxes. In
particular, we elucidate how Hall viscosity enters magnetodrag and modifies its
temperature dependence in the magnetic field.
