Indonesia is the world’s second largest aquaculture producer, with 17,504 islands and 6.4 million square kilometres of sea area. The KKP has set a marine and fisheries sector investment target of IDR 14.47 trillion for 2026, as part of a five-year programme targeting IDR 79.21 trillion by 2029. Government Regulation 78 of 2019 provides a 30 per cent net income deduction for qualifying investments in aquaculture, seafood processing, cold storage development, marine technology, and sustainable fisheries education. The Blue Economy Roadmap entered Phase II in 2025, covering development as a new growth source through to 2029. These are the conditions within which a foreign investor with marine qualifications is operating when they arrive in Indonesia. This article covers the enterprise models available across aquaculture support, coral restoration, cold chain investment, marine technology services, seafood processing, and marine recreation, alongside the KBLI 2025 classification framework, the GR 78/2019 tax incentive structure, the BPOM assessment sequence that must precede any import-dependent business model, the dual yayasan and PT PMA structure for conservation enterprises, and the three structural errors TraceWorthy has been engaged to remediate in this sector.