Underwater soundscapes are fundamental components of reef ecosystems, supporting critical functions including communication, orientation, and recruitment. However, these acoustic habitats are increasingly threatened by anthropogenic noise. Among the various noise sources, recreational diving has emerged as a widespread but under-recognized contributor. Drawing on long-term monitoring at subtropical and tropical reef sites in Taiwan, this chapter presents case examples to illustrate how recreational diving shapes reef soundscapes. Low frequency bubble noise from open-circuit SCUBA systems was found to be a consistent and detectable soundscape feature at reefs with high diver visitation, with daytime noise levels intensifying during weekends, holidays, and peak tourism seasons. These patterns underscore the prevalence of SCUBA noise and reveal a critical gap in marine protected area policies, which rarely address anthropogenic noise. By synthesizing emerging evidence, this chapter highlights the need to integrate the management of recreational diving into conservation planning to safeguard the ecological integrity of reef ecosystems.