This report presents the results of a 2025 industry survey conducted by BIMCO on the operational realities of implementing the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention). The survey captures quantitative and qualitative input from ship operators BWM, with the objective of identifying recurring operational challenges, underlying causes and practical constraints affecting compliance in real trading conditions.
The survey results confirm that, while global implementation of the BWM Convention has reached a mature phase, significant operational challenges persist across ship types, trades and ballast water management system (BWMS) technologies. These challenges are not isolated or exceptional, but systemic and recurrent, particularly during time-critical port operations, cargo handling and ballast uptake or discharge under challenging water quality (CWQ) conditions.
Operational findings indicate that BWMS performance is frequently constrained by environmental conditions, system behaviour and alarm management. Respondents reported frequent alarm cascades, intermittent shutdowns, sensor faults and unpredictable system responses, often occurring at precisely those moments when crew workload is highest. UV-based systems were reported as especially sensitive to CWQ conditions, with low UV transmittance frequently leading to alarms, automatic shutdowns or forced bypass during ballast uptake.
CWQ was identified as a routine and predictable operational reality in many ports, rivers and estuaries, rather than an exceptional circumstance. As a result, reliance on contingency measures was widely reported as a normal component of BWM in practice. Respondents described regular use of contingency pathways in accordance with IMO guidance, triggered by CWQ, system malfunctions, time constraints and extended repair periods due to limited access to authorised service engineers or spare parts. In several cases, defects required more than two months to resolve, during which contingency measures were unavoidable.
Experiences during third-party inspections indicate that BWMS-related findings remain frequent. Inspection challenges were most commonly linked to system malfunctions, alarms, documentation issues and difficulties demonstrating compliance in situations involving contingency measures. Respondents reported inconsistent interpretation of alarms, system behaviour and contingency actions by inspectors, contributing to compliance uncertainty even where crews were operating in line with manufacturer instructions and IMO guidance.
The survey further highlights the significant human-element implications associated with BWMS operation. Frequent alarms, troubleshooting demands and administrative requirements increase crew workload, particularly during port operations, and were reported to contribute to fatigue and, in some cases, rest-hour exceedances. Training was found to be necessary but not sufficient to prevent operational difficulties, with system complexity, environmental constraints and usability issues emerging as more influential factors than training alone.
Taken together, the findings demonstrate that BWMS operation, CWQ, contingency measures, inspection outcomes and human-element impacts are deeply interconnected. The survey does not seek to assess compliance rates or attribute responsibility to specific technologies or manufacturers. Rather, it provides evidence of a structural gap between regulatory assumptions, system design and real-world operation.
