Marine vessel maintenance generates small paint debris that is discharged into the marine environment. The disposal of paint debris remains mostly unregulated despite being a contaminant of emerging concern. In particular, antifouling paint particles (APPs) contain various biocides and chemical additives in their formulation, exhibiting a higher degree of toxicity to marine organisms than most anthropogenic particles, such as conventional microplastics. Although research on the leaching of biocides from antifouling paints has made significant progress, focus on APPs as a whole has only recently emerged. Nevertheless, current studies face several methodological and analytical constraints in elucidating the abundance and nature of APPs in the marine environment. Thus far, the identification and quantification of APPs have been accomplished using exhaustive and time-consuming procedures, typically involving density separation, followed by optical and/or spectroscopic techniques, reporting data on the number, size, shape, color, and polymer types of particles. These measurements may however not reflect the total mass concentration of APPs in samples, as there are limitations in the information these methods can provide, such as generally only being reliable above a specific particle size (i.e., >500 um), given that density separation is not possible due to the high density of APPs. To address this knowledge gap and facilitate the accuracy of environmental monitoring, the current study aims to develop an effective thermal degradation method to provide mass-based concentrations of APPs in highly impacted water and terrestrial environment to better understand the risk of APPs contamination. Given the growing concern for APPs in boatyards and marinas, this study will focus on developing a simple analytical workflow from sampling to data reporting and interpretation.