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Acquisition downtime resulting from bad weather is often a significant factor in the cost of marine seismic surveys. In the North Sea, for instance, seismic data are acquired mostly during the summer, and weather downtime can still amount to 40% of the survey time.Our approach to reducing weather downtime is based on the following concepts:• During multiple acquisition passes, seismic signal is repeatable; bad weather noise is not. •Filtering algorithms are applied to reduce swell noise. •Imaging with least-squares inversion algorithms is less sensitive to noise-edited data than conventional imaging. To test these concepts we acquired multiple pass data covering the same areas in good and bad weather. A survey was made from the Barents sea and the acquisition was performed with a vessel equipped for standard 3D surveys.Commercial 3D data provide a reference for quantitative comparison of seismic images and of attributes derived from the seismic data. The results obtained so far are encouraging, and we expect opportunities for cost-effective reduction of bad weather downtime (10% to 20%) without compromising quality requirements.