Advances in 4D ultrasound imaging open new perspectives in biomedical research by reducing the long-standing challenge of operator dependency. Extensive research efforts are focused on developing next generation of 2D transducer arrays for 4D imaging. Here, we present a compact 2D array design based on hexagonal-shaped transducer elements. We demonstrate that 2D hexagonal arrays provide an optimal compact sampling, resulting in lower grating lobe levels and an improved imaging quality compared to conventional square-shaped transducer element arrays. A prototype array made of hexagonal transducer elements is presented, and its characterization is provided, demonstrating its imaging capabilities.