High-strength steels (HSS) might undergo hydrogen embrittlement (HE) in seawater under cathodic protection (CP) with traditional Aluminum-Indium (Al-In) or zinc (Zn) galvanic anodes. The actual failure risk will also depend on metallurgy, mechanical properties and local loads. Even though super duplex stainless steels (SDSS) generally do not require CP, they can unintentionally become polarized due to electrical continuity with protected carbon steel structures. CP current demand and hydrogen evolution depend on various factors, like dissolved oxygen, temperature, flow, microbial activity, calcareous deposits, and depth. Hence, the risk of HE varies with exposure site and must be assessed. Aluminum-gallium (Al-Ga) is a low-voltage anodic material aimed at reducing protective potential to mitigate HE in high-strength steels in seawater. However, long-term field data is limited. This study aimed to gather long-term CP data for SDSS at different depths and seawater types, and to assess HE risk using Al-Ga vs. conventional anode materials. Instrumented anchored lines, including CP sensors, stressed samples, and environmental sensors were deployed for over a year in shallow, intermediary, and deep seawaters. Results showed varying cathodic current demands, with deep seawater having the highest. Biofilm formation on SDSS caused depolarization at all sites, with differences noted between sites. Al-Ga significantly reduced hydrogen-induced cracks in SDSS.