Dive sites in Finland

The Kronprins Gustav Adolf was a Swedish naval vessel that sank in the waters of the Aland archipelago in the 18th century. The ship was part of the Swedish navy during a period of frequent naval conflicts in the Baltic. The cold, brackish water of the Baltic Sea has preserved the wreck remarkably well, as the low salinity inhibits the shipworm (Teredo navalis) that destroys wooden wrecks in more saline waters. The wreck was discovered by local divers and has since become one of Finland's most significant underwater heritage sites.

This is an advanced dive requiring a minimum of Advanced Open Water certification, though Deep Diver specialty or technical diving certification is strongly recommended given the 42-meter maximum depth. A drysuit is absolutely mandatory, as water temperatures at depth range from 2 to 6 degrees Celsius even in summer. Twin tanks or sidemount configuration with adequate gas planning for the depth and cold are essential. Penetration requires wreck diver certification and appropriate equipment including reels, redundant lights, and stage bottles for decompression.

Diving the Kronprins Gustav Adolf is typically arranged through dive operators based in Mariehamn on the Aland Islands. The wreck site requires a boat trip and experienced local guides who know the exact location and current conditions. The diving season is limited to June through August when weather conditions are most favorable. Advance booking is recommended as trips depend on weather windows and group sizes. Some operators offer multi-dive packages combining this wreck with other Aland shipwrecks.

The waters around Jurmo contain wrecks spanning several centuries of Baltic maritime history. The most notable are wooden sailing vessels from the 17th through 19th centuries, many remarkably well preserved due to the cold, low-salinity, low-oxygen conditions of the Baltic. Some wrecks still have standing masts and intact deck structures. There are also more modern steel-hulled vessels from the early 20th century. Access to certain wrecks requires permits from the Finnish Heritage Agency as they are protected cultural sites. Your dive operator will advise on which wrecks are open for recreational diving.

Jurmo is one of the outermost inhabited islands in the Finnish Archipelago Sea. From Turku you can take the archipelago ferry route via Nagu and Korpo, which takes several hours. Most dive operators based in Turku or Nagu run dedicated boat trips to Jurmo wreck sites during summer months. The crossing can be rough in poor weather, so trips are weather-dependent. Some operators offer multi-day liveaboard-style charters covering several wreck sites around the outer archipelago.