Dive sites in Sweden

The Baltic Sea creates ideal preservation conditions through a combination of factors. The cold water temperatures slow biological decay. The low salinity, roughly one-third that of ocean water, means that the destructive shipworm Teredo navalis cannot survive, protecting wooden hulls that would be consumed within decades in saltwater. The low oxygen levels in deeper Baltic water further inhibit decomposition. These conditions have preserved wrecks in the Baltic for centuries in condition that would be impossible in warmer or more saline waters.

The Norrköping area offers a range of wrecks spanning several centuries of maritime history. These include wooden merchant vessels from the 17th and 18th centuries, iron and steel steamships from the 19th century, and various smaller craft. Some wrecks are identified and documented by the Swedish maritime museums while others remain anonymous. Depths range from 8 to 35 metres, with many of the best-preserved wooden wrecks in the 15 to 30 metre range.

The diving season runs from May through October, with the best combination of visibility and water temperature from June through September. Summer water temperatures reach 15 to 18 degrees in the upper layers, though a thermocline typically develops at 10 to 15 metres with significantly colder water below. Visibility is best in early summer and autumn at 10 to 15 metres. A drysuit is recommended even in summer for the deeper wreck dives below the thermocline.