The low-velocity impact response of 2D granular crystals immersed in various fluids over a wide range of viscosities (1-10(6) cP) was investigated. The drag effects in the immersed crystals results in significantly higher wave attenuation as compared to dry granular crystals. In order to quantify the spatial dependence of the wave decay characteristics, the coefficients of attenuation were computed for the dry granular crystals and granular crystals immersed in various fluids. The coefficient of attenuation for immersed granular crystals was significantly larger than the coefficient of attenuation for dry granular crystals. As the viscosity increased, the coefficient of attenuation also increased due to the additional drag effects followed by an unexpected decrease for the highest viscosity fluids. The ratio of kinetic energy to strain energy for immersed granular crystals decreases initially as a function of viscosity but inatases again for the fluids with the highest viscosities. (C) 2020 Elsevier B.V. All rights reserved.