The forecasts of the optical turbulence in the marine surface layer were made in different seasons based on the products of the numerical weather prediction model. It is found that the seasonal variations of the surface optical turbulence and the atmospheric coherence length are not significant over the oceans between 30°S and 30°N, but much larger over the higher latitude oceans with weaker surface optical turbulence and larger atmospheric coherence length in the summer hemisphere but stronger surface optical turbulence and smaller atmospheric coherence length in the winter hemisphere. The surface optical turbulence strength C(2,n) in the 10 m height above the sea level is greater than 10^－15m^－2/3 for 10.6 μm but less than 10^－15m^－2/3 for 0.55 μm over the most parts of the oceans around the world. If the propagation path was the horizontal path 10 m above the sea level, the atmospheric coherence length is greater than 60 cm for 10.6 μm but less than 6 cm for 0.55 μm over the most parts of the oceans around the world. The horizontal patterns of the forecasted surface optical turbulence strength are similar to each other based on the same time products respectively from the two different numerical weather prediction models, but the horizontal pattern of the forecasted surface optical turbulence is much sharper with the higher model horizontal resolution.