Offshore wind expansion in the North Sea is putting pressure on maritime safety, as increasing fixed infrastructure reduces manoeuvring space and increases collision and disruption risk. This thesis examines how shipping safety is integrated into offshore wind planning as the sector scales up. It compares governance arrangements in the Netherlands and the United Kingdom, two mature offshore wind contexts with similar geography but different institutional designs.

The central research question asks how vertical coordination, horizontal coordination, Safety-I/Safety-II approaches, and compliance design shape the integration of shipping safety into offshore wind planning in both countries as offshore wind scales up. The study applies a comparative case design combining document analysis and expert interviews, structured around four analytical dimensions: vertical allocation of responsibilities, horizontal cross-sector coordination, safety mode (Safety-I versus Safety-II), and dual-layer compliance architecture.

Both countries channel navigational safety through a multi-stage governance funnel, but differ in where safety alignment is stabilised. The Netherlands employs upstream stabilisation through plan-led steering: safety principles and spatial assumptions are embedded early via marine spatial planning and state-led site preparation, pushing consequential trade-offs to pre-tendering stages. The United Kingdom relies on downstream stabilisation through developer-led proof in consenting: early screening processes exist, but most safety issues are resolved through Navigational Risk Assessments and evidence during the consenting phase, preserving flexibility while increasing vulnerability to late lock-in and costly redesign.

Several findings emerge. Decision power does not eliminate the need for evidence, but it changes how evidence must be produced and justified. Safety-I continues to provide the non-negotiable prescriptive baseline, while Safety-II is growing in importance as sea space becomes denser and cumulative risks harder to anticipate through incident-based learning alone. Scenario modelling, near-miss learning, and structured learning loops are becoming essential evidence-production tools. Both systems depend on a dual-layer compliance structure combining prescriptive baselines with performance-based proof, but this functions robustly only when review capacity, consistent methods, and shared data baselines are in place.

Based on these findings, the thesis identifies four practical priorities for strengthening navigational safety governance as offshore wind scales. Institutionalising anticipatory evidence production through routine scenario-based reviews and near-miss learning. Strengthening upstream screening before commercial and procedural lock-in occurs. Investing in review capacity and consistency so regulators can evaluate deviations from prescriptive baselines transparently. Building a shared evidence base of traffic patterns, manoeuvring needs, and port practice projections to enable cumulative impact assessment across projects and institutions.