Abstract: A centrifugal slurry pump including a specifically designed impeller having circumferentially spaced vanes mounted between a back disc-shaped shroud and a front open annular shroud. The vanes are thick in cross-section for wear-resistance and channels between adjacent vanes permitting a relatively large spherical objects, such as rocks which are encountered during dredging operations, to pass therethrough, the objects having a diameter of in excess of 15 inches, while maintaining an efficiency in excess of 80% and a head in excess of 30 feet. The vanes further preferably have a mixed pitch and a negative overlap with quite large channels between adjacent vanes so as to pass the large spherical objects.