Abstract: A high capacity marine separator (30) is disclosed which uses a first stage formed by an inertial vane separator (32), a second stage formed by a coalescer stage (36) and a third stage formed by an inertial vane separator (34). The coalescer stage (36) is canted from vertical relative to the air flow direction which increases the surface area for air flow, increases the drainage rate of water from the coalescer section and provides an improved air flow distribution to the second inertial vane separator with higher velocities near the top of the second inertial vane separator. The inertial vane separators (32, 34) have flush cavities to reduce obstruction to air flow and have vanes that are greater than three inches in wavelength and spaced greater than one inch apart. The marine separator is capable of flow velocities of 50 standard feet per second.