Offshore renewable energy holds promise for sustainably achieving Net Zero Emissions commitments. However, offshore industries transform land and seascapes with resultant trade-offs for both nature and people. Cumulative impacts have long been a challenging issue for environmental management, creating uncertainty around development limits in a region and risks to financial investments, particularly for nascent industries and governments striving to meet tight deadlines for international commitments. In this talk, I will provide evidence-based recommendations for improved cumulative impacts accounting in offshore renewable energy to streamline environmental assessments and better manage impacts within and across sectors. I will demonstrate opportunities and challenges of implementing these recommendations using offshore wind project proposals in Australia, with a focus in the Bass Strait.