Informal patron-client arrangements in capture fisheries can combine vessel finance, employment, social assistance, and market control, creating both protection and dependency. This study examined how boat owner-crew labor relations are reproduced and how a feasible transformation could be designed at Tenau Coastal Fishing Port and Oeba Fish Landing Base, Kupang City, Indonesia. A qualitative case study with descriptive economic support used observations, in-depth interviews, structured questionnaires, and document review from April to November 2024. The principal participants comprised 20 matched dyads, each consisting of one boat owner and one crew member; collectors, port managers, and local-government actors were supporting informants. The Theory of Planned Behavior (TPB) was used to explain why the existing arrangement persisted, while Soft Systems Methodology (SSM) translated the diagnosis into a purposeful activity system and staged intervention strategy. Owners financed vessels and operations and controlled first-sale decisions and records, whereas crew members supplied labor but did not determine buyers, prices, or post-landing revenue allocation. The arrangement persisted because crew work provided income and social support under limited alternatives, while owners sought to protect capital, manage risk, secure labor, and coordinate marketing. Norms of loyalty, gratitude, kinship, and informality reinforced these constraints. The analysis produced one multi-actor root definition and eight minimum activities for shifting opaque and dependency-based relations toward more transparent, clearly defined, and balanced arrangements. The strategy begins with shared information, followed by minimum work agreements and mediation, crew economic capability, and alternative economic access. Social-norm change, behavioral constraints, and system redesign must therefore be addressed together without disregarding the legitimate financing and risk-bearing role of boat owners. Methodologically, the sequential integration of TPB and SSM links behavioral explanation to conceptual system redesign.
