Scotland’s marine and coastal ecosystems underpin a healthy, productive and resilient economy and society. They provide essential services including climate regulation and carbon storage, fisheries and food production, coastal protection, biodiversity, renewable energy space, and opportunities for tourism and recreation. These systems are dynamic and interconnected, with benefits and pressures flowing across land, coast and sea. Scotland has committed to halting biodiversity loss by 2030 and restoring ecosystems by 2045, but achieving these ambitions will require sustained investment at a time of significant pressure on public finances. In response, the Scottish Government’s Natural Capital Market Framework (2024) signals a growing role for responsible, values-led private investment to complement public funding. The accompanying Principles for Responsible Investment in Natural Capital set clear expectations around environmental integrity, community engagement, ethical practice and public benefit. However, these principles were developed primarily under terrestrial contexts. At the same time, interest in mobilising private investment for marine and coastal restoration is accelerating, reflected in the Draft Marine and Coastal Restoration Plan and emerging blue carbon initiatives. This policy brief examines how Scotland’s existing principles can be meaningfully adapted for coastal and marine environments. It adopts a Source-to-Sea perspective, recognising that environmental outcomes are shaped by interactions across land, coast and sea, and that governance and investment frameworks must reflect these connections. The brief focuses on a natural capital approach to nature finance: private investment for environmental outcomes guided by natural capital principles and designed to deliver multiple ecological and societal benefits, with transparency, integrity and long -term stewardship. The emphasis is on the conditions under which finance is mobilised and governed, rather than on any single financial mechanism. This policy brief is intended for policymakers, regulators and public agencies responsible for Scotland’s coastal and marine environment, including the Scottish Government, NatureScot, Crown Estate Scotland, SEPA, local authorities and regional marine planning partnerships. It will also be of interest to practitioners, researchers, community organisations and responsible investors engaged in marine and coastal restoration and stewardship. The outputs presented here draw on a cross-sector workshop convened in May 2025, involving academics, policymakers, regulators, practitioners and industry. Discussions highlighted a consistent set of challenges that distinguish coastal and marine contexts from land-based nature finance. These include the limited availability of marine-specific standards and verification frameworks; a tendency to prioritise active intervention and easily measured outcomes (particularly carbon), despite evidence that pressure reduction and passive recovery are often more effective; persistent gaps in ecological and social baseline data; and misalignment between short-term financial expectations and long-term, non-linear ecological recovery. Governance complexity, diffuse and non-geographically anchored communities, and unclear benefit-sharing arrangements further complicate delivery. At the same time, these challenges point to clear opportunities. Scotland already has well - established marine governance frameworks, including marine planning, licensing and seabed leasing, that provide practical entry points for embedding shared expectations. There is strong support for developing coastal and marine-specific restoration and recovery standards.