50 free Baltic Sea trivia questions with answers — geography quiz, new questions added Aug 2026.
Baltic Sea trivia for geography fans, cruise passengers, Nordic and Baltic expats and pub-quiz setters. The quiz starts with the basics - which nine countries touch the sea, where it drains, why its water is barely salty and why the shipworm leaves old wrecks alone - and then works through the gulfs, islands and straits: Bothnia and Finland, Gotland and Bornholm, Åland, the Curonian Spit, the Sound Dues once collected at Kronborg. History gets its share: Tacitus and Adam of Bremen naming the sea, Vikings calling it Austmarr, the Hanseatic League and its cogs, Sweden's dream of a Mare Nostrum Balticum, Peter the Great founding St Petersburg on the Neva, the loss of the Vasa in 1628, the sinking of the Wilhelm Gustloff in 1945 and the ferry Estonia in 1994, Cold War submarines, the Øresund Bridge, Nord Stream and the 'NATO lake' of the 2020s. Roughly a third of the questions are easy, a third medium and the rest will stretch anyone who did not grow up on its shores. Every answer has been checked against a reference page and each question shows its source once you have answered.
30 of 50 questions with answers and explanations. Play the quiz
Q 01How many countries have a coastline on the Baltic Sea?
Nine
Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia and Sweden; Belarus, Norway and others lie only in the drainage basin.
Q 02The Baltic is the world's largest basin of what kind of water?
Brackish
Its open surface water is under one percent salt, so drinking it in an emergency would actually hydrate you, unlike ocean water.
Q 03Which sea does the Baltic drain into through the Danish Straits?
The Kattegat
The three straits are the Øresund, the Great Belt and the Little Belt; from there the water reaches the Skagerrak and the North Sea.
Q 04Which artificial waterway, opened in 1895 through Schleswig-Holstein, links the Baltic to the North Sea?
The Kiel Canal
It saves ships about 460 km compared with going round Jutland and averages some 32,000 transits a year, making it one of the busiest artificial waterways on Earth.
Q 05What is the northern arm of the Baltic, lying between Sweden and Finland, called?
The Gulf of Bothnia
Its northernmost basin, the Bothnian Bay, is where the sea ice forms first each November and where about two-thirds of fish species are freshwater ones.
Q 06Which arm of the Baltic connects the sea to Saint Petersburg?
The Gulf of Finland
Russia's tsar put his new capital at the mouth of the Neva at the gulf's eastern end after Sweden's defeat in the Great Northern War.
Q 07What is the maximum depth of the Baltic Sea, at the Landsort Deep on the Swedish side?
About 459 m
The average depth is only about 55 m, which is one reason the sea is so easily freshened by river runoff.
Q 08Which Roman historian described the 'Suebic Sea' (Mare Suebicum), an early name for the Baltic, in AD 98?
Tacitus
He noted the ice breaking up and floating in spring; Ptolemy preferred 'Sarmatian Ocean' and Jordanes called it the Germanic Sea.
Q 09Which 11th-century German chronicler first called it the 'Baltic Sea', likening it to a belt?
Adam of Bremen
The name only became dominant after 1600, and 'the Baltics' for the lands east of the sea dates from the 19th century.
Q 10In German, Swedish, Danish and most other Germanic languages the Baltic is called the equivalent of what?
East Sea
Estonian goes the other way and calls it the West Sea, which is geographically correct for Estonia; Finnish uses 'East Sea' too, probably a relic of Swedish rule.
Q 11What did the Vikings call the Baltic, a name meaning 'Eastern Sea' that appears in the Heimskringla?
Austmarr
Saxo Grammaticus recorded an older name, Gandvik, whose '-vik' ending shows the Vikings correctly saw it as a bay of the ocean.
Q 12Which fossilised resin has been harvested on the Baltic's south shores since the 12th century?
Amber
The richest deposits lie in what are now Poland, Russia's Kaliningrad region and Lithuania.
Q 13Which federation of merchant towns, grown from Lübeck, dominated Baltic trade from the 13th to 16th centuries?
The Hanseatic League
Its emblematic ship was the cog, and its trading posts or Kontors in London, Bruges, Bergen and Novgorod enjoyed legal autonomy.
Q 21The ferry MS Estonia sank in September 1994 while sailing between which two cities?
Tallinn and Stockholm
An inquiry found the locks on the bow visor failed, letting water flood the car deck and capsize the ship in minutes.
Q 22Why do old wooden wrecks such as the Vasa survive so well on the Baltic seabed?
The cold brackish water keeps out the shipworm
The Vasa spent 333 years underwater off Stockholm and was raised with a largely intact hull in 1961.
Q 23How far did the Swedish warship Vasa get into her maiden voyage in 1628 before she sank?
About 1,300 metres
Q 14What was the emblematic ship type of the Hansa merchants, depicted on its seals and coats of arms?
The cog
By the end of the Middle Ages it gave way to the hulk and then to larger carvel-built ships.
Q 15Which Latin phrase named the goal of Poland, Denmark and Sweden's 16th–17th-century wars for control of the sea?
Dominium maris baltici
Sweden came closest, and in the 17th century spoke of Mare Nostrum Balticum, 'Our Baltic Sea', though the Dutch dominated the actual trade.
Q 16At which castle near Helsingør did Denmark collect its Sound Dues from ships passing through the Øresund?
Kronborg
Dues were also taken at Nyborg on the Great Belt and at Fredericia on the Little Belt; the castle is better known as the Elsinore of Hamlet.
Q 17Which Russian ruler founded Saint Petersburg at the mouth of the Neva to secure a Baltic outlet?
Peter the Great
Sweden's defeat in the Great Northern War handed Russia the eastern coast, and it stayed the dominant Baltic power thereafter.
Q 18In the Crimean War, Russia's Bomarsund fortress was destroyed in which Baltic archipelago?
Åland
The Baltic campaign is sometimes called the Åland War; the fleet also bombarded Sveaborg off Helsinki and Kronstadt off St Petersburg.
Q 19The January 1945 sinking of which German transport ship remains the worst maritime disaster in history?
Wilhelm Gustloff
Torpedoed by a Soviet submarine while evacuating East Prussia, she took roughly 9,000 people down with her in freezing water.
Q 20Which Soviet submarine commander sank the German evacuation ship Gustloff on 30 January 1945?
Alexander Marinesko
He shadowed the ship on its seaward side for two hours, then swung round to attack from the landward side where no one expected a submarine.
Top-heavy and unstable, she went down minutes after meeting a wind stronger than a breeze; the inquiry punished nobody.
Q 24Since 1720, how many times has the Baltic Sea frozen over entirely, most recently in early 1987?
20
In a typical winter the Gulfs of Bothnia, Finland and Riga freeze; the whole sea did not freeze even in the severe winter of 2010-11.
Q 25Roughly what fraction of the Baltic Sea's surface is ice-covered at an average winter's peak?
About 45%
The ice peaks in February or March; the northern Bothnian Bay is the first to freeze and the last to thaw, sometimes holding ice into June.
Q 26Which two seal species depend on the sea's winter ice, one of them breeding only on it?
Grey and ringed
Only the ringed seal suffers in ice-poor years, because it feeds its pups exclusively on the ice; the grey seal can breed ashore.
Q 27What are the occasional pulses of salty, oxygen-rich North Sea water that flush the deep basins called?
Major Baltic inflows
Small ones happen about yearly, but pulses big enough to replace the anoxic water in the deep central basin come only about once a decade.
Q 28Approximately what share of the Baltic seafloor is a variable 'dead zone' with almost no oxygen?
A quarter
Dense salty water sits on the bottom cut off from the air, and bacteria there release hydrogen sulphide; fertiliser runoff has made summer algal blooms worse.
Q 29Which is Sweden's largest island, home to the Hanseatic town of Visby?
Gotland
Visby hosts the political festival Almedalen Week and a Medieval Week each summer; in 1361 Valdemar Atterdag of Denmark invaded and killed some 1,500 local farmers.
Q 30Which Danish Baltic island is famous for its round churches and the fortress ruin of Hammershus?
Bornholm
Soviet troops bombed and occupied it in May 1945 and did not leave until April 1946; in 1953 a Polish pilot defected there in a MiG-15.