We present a real-time operational model and full GPU implemented tsunami simulators for ocean-wide areas. The use of GPUs provide a fast calculation of the shallow water equations. These are solved using the method of characteristic and upwind cubic interpolation. High accuracy and stability is obtained by using these schemes. A tailor-made refinement was developed for our simulator, this uses distance from the coast and focal areas to generate a memory-efficient domain and to track accurately coast shapes. In order to speed-up computation three optimized GPU kernels were developed (wet, wall and inundation) to use in specific regions of the domain. Good agreement was found when compared against well-established tsunami benchmark problems. Hind cast of the 2004 Indonesia tsunami is presented as a case study of a real tsunami ocean-wide case. Arrival times and wave heights results are checked. Tests runs on Tsubame 3.0 using three Tesla P100 cards fully simulated 10 hours of this tsunami is under 10 minutes