The record, made with the Monizee system's buoy network, showed that, between Saturday and Tuesday, “with the passage of the Hermínia depression, a worsening of the sea state was observed on the northwest coast of mainland Portugal, namely at the buoys located in Leixões and Nazaré”.

According to the Hydrographic Institute, the other maximum wave height values ​​were observed at the Leixões ocean buoy, with a maximum height of 15 metres and a significant height of 9.5 metres, on Monday night and, on that same night, with 16.2 metres in maximum height and nine metres in significant height at the Leixões coastal buoy, in the Porto district.

The Nazaré ocean buoy recorded a maximum height of 15.6 metres and a significant height of 9.4 metres in the early hours of Tuesday. The coastal buoy of this town in the district of Leiria also recorded a significant height of 9.9 metres on Monday night.

Currently, the Hydrographic Institute maintains in operation, within the scope of the Monizee system (https://www.hidrografico.pt/iprojeto/3), a set of coastal ocean monitoring networks off mainland Portugal.

Sea conditions can be monitored on the page https://geomar.hidrografico.pt or on the Hidrografico+ App.