For SAR image waters edge detection

the traditional algorithm can not suppress speckle noise，so there are many false edges in the results. Based on Shearlet transform

a kind of multi-scale geometric transformations

which represent curves accurately and effectively

we propose an improved Shearlet transform. Combining improved Shearlet transform with clustering and snake model

a new method of waters edge detection for SAR image is performed. Experiments show that new method can not only reduce influence of speckle noise

but improve the integrity and accuracy of edge detection

and it is efficient and effective for SAR image waters edge detection.