A golf ball (20) having a low volume cover layer (14) is disclosed herein. The golf ball (20) has a cover layer (14) with a volume less than 0.1550 cubic inches. In a preferred embodiment, the cover layer (14) is composed of a reaction-injection molded polyurethane material. Preferably, the cover layer (14) has a plurality of deep depressions (99) with either a plurality of multi-faceted polygons (44) or dimples.