A time-domain hybrid method developed by authors is applied to estimate the unsteady wave field of ships advancing in waves. The method is combining the Rankine panel method applied in the near field and the Green function method applied in the far field of ships, and it makes possible to satisfy the radiation condition exactly at least from theoretical point of view. The method is, therefore, the mostly expected among many numerical methods to be reliable on the satisfaction of the radiation condition even in the low-frequency region where the κ₂ wave system propagates upstream of ships. The wave elevation is used as a typical physical-value which represents the wave field around ships. The computed wave elevation by the present method is compared with experimental results and with another numerical result by the Rankine panel method. Through the comparison, it is confirmed that the present hybrid method can estimate the wave elevation with high accuracy and applicable to the low-frequency region without losing accuracy.