The Moored MultiMode Multibody (M4) prototype was deployed in King George Sound, the outer harbour in Albany, Western Australia, in 2024. It is a surface-riding attenuator type wave energy converter deployed for a 6-month sea trial. This present study is an ancillary science program and evaluates the growth and distribution of marine organisms on the device, which was not antifouled. The device aligns to the prevailing winds – usually easterlies. We expect growth to be affected by the usually northward-facing port side being exposed to more sunlight and the front to stronger wave action than the rear. The biomass of organisms was estimated using photographs and scrapings. Species were identified visually and by e-DNA analysis. The M4 was instrumented to analyse device motion, allowing this study to relate Reynolds numbers to potential impact on growth rates of organisms. Impact was quantified by comparing growth under different stress conditions (motion) and exposures (sides, orientation, depths). Changes in biofouling because of short periods the M4 spent in a sheltered marina were compared to the high-energy ocean environment. This study is generally relevant to offshore developments, but particularly in temperate climate waters in the context of ocean renewable energy installations.