Architecting a National Marine Spatial Data Infrastructure: A Tiered, Adaptive Strategy for Translating Diagnostic Gaps into Executive Action

Persistent underperformance in National Marine Spatial Data Infrastructure (NMSDI) is frequently associated with implementation pathways that prioritize technology delivery over enforceable coordination—treating the NMSDI as a finite project rather than a durable national capability. This study developed and tested an implementation-oriented approach that converts institutional diagnostics into staged, monitorable execution by linking the governance problem structure to an executable strategy implementation plan (SIP). The workflow is designed to be procedurally transferable within stated boundary conditions. A convergent mixed-methods design integrated national stakeholder evidence with an international benchmark to derive a comparative gap diagnosis. Priorities were produced via an explainable severity–feasibility MCDA and stress-tested for stability under alternative assumptions. Across the ranking outputs, governance-related barriers emerged as higher-priority than purely technical or resource constraints. The most consequential impediments concerned authority and decision-rights ambiguity, fragmentation across responsible institutions, and the absence of governed exchange mechanisms—conditions that systematically constrain data reuse and cross-sector decision coordination even when platforms and standards are available. On the basis of this diagnosis, the resulting SIP provides a tiered, governance-first execution architecture that sequences enabling coordination mechanisms ahead of large-scale technology rollout and uses explicit dependencies and review gates to support adaptive delivery under uncertainty. The study reframed the NMSDI as an integrated hydrospatial information framework in which hydrospatial services function as a national decision-support and coordination capability.