The planned construction and maintenance of wind farms in Poland and various marine research activities (such as seabed surveys and environmental studies) can only be carried out when weather conditions permit – primarily when sea waves are not too high. Knowledge of periods when atmospheric conditions are suitable (“weather windows”) allows for better work planning, ensures safety, and minimises delays and reduces work costs.
Published in Nature, the study by scientists from Gdynia Maritime University (Maria Kubacka, Dariusz Barbucha, Adam Krężel and Juliusz Gajewski) analyses weather windows in the Polish Exclusive Economic Zone of the southern Baltic Sea, assessing the spatial and temporal variability of sea conditions.
Polish Energy Policy and the sea
Poland’s Exclusive Economic Zone is a maritime area in the Baltic Sea extending up to 200 nautical miles from Poland’s coastline where the country has sovereign rights for exploring, exploiting, conserving, and managing natural resources, both living and nonliving.
As outlined in the Energy Policy of Poland, the country plans to build numerous offshore wind farms that will supply 13% of electricity by 2030, increasing to 19% by 2040. Currently, nine offshore wind farm projects are underway within Poland’s EEZ, with all necessary location permits already secured.
Ph: Freepik
Thorough survey planning and implementation help to reduce geohazards and lower operational expenses by avoiding delays throughout construction and maintenance periods. Given that offshore developments carry substantial risks – largely due to operations in difficult environments subject to unpredictable weather conditions – properly coordinated marine surveys play a vital role in optimising project schedules and maintaining safe working environments. These operations will necessarily involve the deployment of different types of vessels.
The meaning of sea waves
Researchers highlight that the Baltic Sea experiences comparatively mild wave conditions relative to the North Sea or open ocean settings, making the construction and maintenance of offshore wind infrastructure less challenging while enhancing the overall resilience and longevity of the structures. This advantage, however, does not guarantee ideal working conditions year-round.
The research aimed to determine the most practical and appropriate parameters to facilitate various maritime activities, including pre-investment marine studies. Drawing on these findings, the team created accessibility maps depicting theoretical operating hours, offering clearer insights into optimal timing and locations for conducting efficient maritime research.
The study examined safe operating periods in the southern Baltic Sea using weather data from 1940-2022, focusing on four wave height limits (0.5m, 1.0m, 1.5m, and 2.0m). Researchers analysed 24 measurement points, with special attention to two contrasting locations: Location A in open water and Location B nearer to shore. They calculated how often and for how long vessels could safely operate in these areas, looking at periods of at least 12, 24, and 48 hours.
Better and safer conditions
The analysis of historical wave data across 82 years revealed significant seasonal and spatial variability, with shallow coastal waters offering better operational conditions, particularly along Poland’s western and southeastern coasts. For higher wave thresholds, operating time increased considerably offshore, with accessibility reaching up to 95% in May in certain areas – better than many other places in Europe.
The best time for offshore work in Polish waters is between May and September, while winter months offer very little working time when waves need to be smaller. This information helps companies plan better, choose the right harbours, and schedule projects more efficiently.
Researchers emphasised that the study has some limitations. It only looked at wave heights and didn’t consider other important factors like visibility, ice, or wind. The researchers used historical data which might not perfectly predict future conditions. They suggest that future studies should include these other weather factors and compare the predictions with real-life working times.
More
- Kubacka, M., Barbucha, D., Krężel, A. et al.Spatial and seasonal accessibility of marine research weather windows in the polish exclusive economic zone. Sci Rep 15, 7094 (2025). https://doi.org/10.1038/s41598-025-91525-8
- Energy Policy of Poland, https://www.gov.pl/web/climate/energy-policy-of-poland-until-2040-epp2040
