Offshore construction projects are widely recognized as high-risk ventures due to the combined effects of technical complexity, uncertain weather conditions, market volatility, and regulatory pressures. These factors often lead to persistent cost overruns and schedule delays, making robust risk governance essential. This study identifies and evaluates critical cost and schedule risks by developing a consolidated register that integrates both categories and supplements it with a trigger-based early-warning mechanism. A mixed-method approach was employed, combining expert interviews, risk workshops, and project documentation to capture risk evidence and validate findings. The results reveal that procurement cost escalation, contractor variation claims, and rising labor costs represent the most significant financial risks. In contrast, contractor mobilization delays, fabrication spillovers, and extreme weather events constitute major threats to schedule performance. Opportunities such as reducing offshore manpower requirements and optimizing vessel allocation were also systematically included, illustrating the importance of balancing risks with potential efficiency gains. The proposed trigger mechanism, incorporating indicators such as steel price fluctuations, vendor deviations greater than 10%, and extended weather forecasts, demonstrated practical effectiveness in anticipating disruptions before they escalated. By integrating risks, opportunities, and triggers into a unified register, this research advances current risk management practice from reactive documentation to proactive monitoring. The findings contribute to both theory and practice, offering insights that can support project managers, contractors, and regulators in enhancing the resilience and reliability of offshore projects.