Triboelectric nanogenerators (TENGs) possess significant advantages in blue energy harvesting due to their high efficiency, low cost, and ease of fabrication. We present a novel TENGs configuration for harvesting ocean wave energy – Rotary Foam Buoy Energy Harvester (RFBEH), drawing conceptual inspiration from ballpoint pen click mechanism, which comprises a sleeve assembly, a perforated rotating housing, a helical rotary shaft, a linear bearing, foam buoy modules, RF-TENG (Rotational Free-standing Triboelectric nanogenerator) and an upper plate. Under 20 cm wave-height excitation, the perforated rotating housing coupled with a helical rotary shaft transformed low-frequency reciprocating linear motion (0.5 Hz) into 2 Hz high-frequency rotation, achieving a fourfold frequency amplification, which further generates electricity through triboelectric effect by freestanding triboelectric-layer mode, thereby enabling energy harvesting functionality in low frequency environments. The surface potential distribution of multi-paired free-standing triboelectric layer configurations integrated into the RFBEH was systematically analyzed. We engineered a precision testbed to characterize RF-TENG under 10-cm strokes at 30–120 rpm. Moreover, the RFBEH was deployed in a custom wave pool, under 10-cm irregular waves. The RFBEH not only demonstrates a viable TENG-based framework for sustainable wave energy harvesting but also provides groundbreaking methodological insights applicable to energy harvesting systems operating at ultralow frequencies, thereby establishing a theoretical foundation for next-generation blue energy technologies. These findings provide an important example of the floating water wave energy harvesting devices.