Comparing the antifouling efficacy of UVC used in conjunction with marine coatings for two static immersion test sites on the east coast of Florida

Biofouling is a major issue in the marine and shipping industry. Marine coatings have been predominantly used in its management. Ultraviolet-C (UVC) treatment has been gaining interest as an antifouling method and recently has been under consideration for use in conjunction with coatings. A two-part study was conducted to investigate the efficacy of using UVC in preventing biofouling on ship hull coatings. The first part performed a test site comparison of UVC's efficacy in synergy with marine coatings for three months between an estuarine and an oceanic environment. The turbid, estuarine environment showed a higher abundance of biofouling compared to the oceanic site. Location factors like temperature and turbidity determine the biofouling rate and composition. Turbidity attenuates UVC transmission and affects its performance. Results demonstrate the importance of location-specific regime in terms of UVC duty cycling and coating compatibility in the environment of operation. The second part performed a long-term assessment of UVC with the same marine coatings at the oceanic site. After nine months of immersion, the results showed that UVC was effective at preventing macro-fouling on four different marine coatings. A chemical analysis of coatings post UVC exposure in the field environments demonstrated that silicone coatings were the most susceptible to chemical induced changes from UVC, but in general, all coatings had minimal impacts to the surface chemistry. Here, UVC, combined with marine coatings, has proven to be an effective fouling control tool in low turbid waters across a larger temporal scale.