In order to study the lubrication performance of rubber-supported water-lubricated thrust bearings (RWTBs) with polymer coated pads and optimize the offset ratio of rubber cushions, a Thermo-Elasto-Hydrodynamic lubrication performance computational model is proposed. Case studies show that there are concave and convex deformations on the polymer surface under certain load and speed conditions. Deformations decrease the minimum film thickness by 10.9% compared with that calculated without considering deformation. Optimization indicates that the optimum offset ratios of the rubber cushion are 0.585-0.59 in circumferential and 0.49-0.5 in radial direction, and both of them are independent of speed and load. The research verifies that the proposed model is an effective tool for studying lubrication performance and optimizing of RWTBs.