The weather was dominated by moderate winds from south to southwest. The sea surface temperatures as well as the surface nutrient concentrations were normal for the season. The spring-bloom had not yet started in any area. The bottom water at station BY4 in the Bornholm Basin was oxygenated; concentrations over 4 ml/l were measured. Oxygen concentrations lesser than 2 ml/l were found below 70m in almost the rest of the Baltic Proper. Hydrogen sulphide was observed from 80m in the Bornholm Deep (BY5), from 125m at BY10 and from 150 m depth in the Gotland (BY15) and Fårö Deep (BY20).