Flow past two tandem cylinders near a free surface is studied numerically at a Reynolds number of 180 using level set method and immersed boundary method. Values of Froude number are varied as 0.3,0.4,0.6; inter-cylinder distance varied as 2,3,4,5,6,10; submergence depth varied as 0.3,0.55. Flow characteristics and mean forces are noted with the variation of these parameters. Upon examination, it is observed that cylinder-to-cylinder proximity along with increased Froude number reduces the instabilities in flow. It is also found that mean drag of the rear cylinder reduces or increases at certain inter-cylinder distance depending on the submergence depth. At the same time, mean lift is observed to be sensitive to variation in submergence depth for flows with low Froude number. © 2019