Caribbean Sea Trivia
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97 free Caribbean Sea trivia questions with answers — geography quiz, new questions added Aug 2026.
This Caribbean Sea trivia quiz is about the body of water itself rather than the islands around it: where it starts and stops, how deep it goes, what lives in it and how it got its name. The easy questions are ones any beach-goer can try: which ocean it belongs to, which peninsula and which big islands bound it, what its name comes from, when hurricane season runs and what famous canal links it to the Pacific. From there it moves through the straits that connect it to the Atlantic and the Gulf of Mexico, the five basins of its floor, the currents that sweep through it and the reefs that line its western shore. The harder end is for geographers and divers: the Cayman Trough, the Caribbean plate, the Anegada Passage, the age of the sea, Kick 'em Jenny, the Great Blue Hole, Isla de Aves, the extinct Caribbean monk seal, the lionfish invasion, the Great Atlantic Sargassum Belt, coral bleaching figures, the tsunami threat and the odd fact that Barbados and Trinidad are officially in the Atlantic. A few questions on Columbus, pirates and rum round it out. Every answer was checked against encyclopaedia entries on the sea, its straits, reefs and wildlife before publishing, and the supporting sentence is stored with each question. If you enjoy this one, try our Caribbean, oceans and coral reef quizzes next.
30 of 97 questions with answers and explanations. Play the quiz
Q 01The Caribbean Sea lies southwest of which sea, famous for its floating seaweed?
The Sargasso Sea
The Sargasso Sea, the only sea bounded by currents rather than land, lies in the North Atlantic northeast of the Caribbean and is named for the floating sargassum seaweed that gathers there.
Q 02Which is the largest island in the Caribbean Sea?
Cuba
Cuba, at roughly 110,000 square kilometres, is the largest Caribbean island; Hispaniola, shared by Haiti and the Dominican Republic, is second at about 76,000.
Q 03The Greater Antilles form the sea's northern boundary, running from Cuba east to which island?
Puerto Rico
The Lesser Antilles then take over, curving south from the Virgin Islands.
Q 04Roughly how large is the Caribbean Sea?
About 2,750,000 sq km
The Caribbean Sea covers about 2,750,000 square kilometres, making it one of the largest seas on Earth, larger than the Mediterranean's roughly 2,500,000.
Q 05What is the deepest point of the Caribbean Sea?
The Cayman Trough
The Cayman Trough, between Jamaica and the Cayman Islands, reaches about 7,686 metres, the deepest point in the Caribbean Sea.
Q 06The transform fault of the sea's deepest trough continues onshore into Guatemala as which fault system?
Polochic-Motagua
The Polochic-Motagua fault system in Guatemala is the onshore continuation of the Swan Islands transform fault that bounds the Cayman Trough; the trough itself contains the slowly spreading Mid-Cayman Rise.
Q 07Which barrier reef, the largest in the Western Hemisphere, runs along Central America's Caribbean coast?
The Mesoamerican Barrier Reef
The Mesoamerican Barrier Reef, also called the Great Mayan Reef, stretches about 1,000 km from Mexico's Yucatán Peninsula to Honduras and is the largest barrier reef in the Western Hemisphere.
Q 08Which four countries does the Great Mayan Reef run along?
Mexico, Belize, Guatemala, Honduras
The reef runs about 1,000 km along Mexico, Belize, Guatemala and Honduras, from Isla Contoy off the tip of the Yucatán to the Bay Islands of Honduras.
Q 09The Belize Barrier Reef was declared a World Heritage Site in which year?
1996
UNESCO inscribed the Belize Barrier Reef Reserve System in 1996; its seven protected areas cover about 963 square kilometres of the Mesoamerican reef.
Q 10Which strait between Cuba and Haiti lets Atlantic water into the Caribbean?
The Windward Passage
The Windward Passage, about 80 km wide between eastern Cuba and northwestern Haiti, is a main Atlantic entry to the Caribbean and lies on the Panama Canal to US east coast shipping route.
Q 11The Yucatán Channel links the Caribbean Sea with which body of water?
The Gulf of Mexico
The Yucatán Channel, about 217 km wide between Cuba and Mexico's Yucatán Peninsula, joins the Caribbean Sea to the Gulf of Mexico and is nearly 2,800 metres deep near the Cuban coast.
Q 12The Mona Passage separates which two islands?
Hispaniola and Puerto Rico
It was the site of a devastating earthquake and tsunami in 1918.
Q 13The Anegada Passage separates the British Virgin Islands from which island?
Sombrero
Sombrero, a flat uninhabited rock belonging to Anguilla, lies across the Anegada Passage from the British Virgin Islands; the strait, about 2,300 metres deep, is the main deep-water route between the Atlantic and the eastern Caribbean.
Q 21How many magnitude-7.5+ earthquakes hit the Caribbean in the 500 years before 2010?
About a dozen
About a dozen earthquakes of magnitude 7.5 or greater struck the Caribbean region in the five centuries to 2010; the 12 January 2010 Haiti quake, though only magnitude 7.0, killed at least 100,000 people.
Q 22By roughly how much do the Caribbean's monthly mean surface temperatures vary across the year?
About 3 °C
Monthly average surface temperatures vary by no more than about 3 °C over the year, from roughly 25.5 °C in winter to 28 °C in summer, a mark of the sea's highly homogeneous hydrology.
Q 23Which ocean current, entering from the tropical Atlantic, chiefly drives the Caribbean's climate?
The North Equatorial
Q 14Into how many basins is the Caribbean seafloor divided?
Five
Five basins make up the seafloor: the Yucatán, Cayman, Colombian, Venezuelan and Grenada basins, separated by underwater ridges such as the Beata Ridge and the Aves Ridge.
Q 15Which Colombian archipelago in the western Caribbean lies far closer to Nicaragua than to Colombia?
San Andrés
San Andrés, with Providencia and Santa Catalina, forms a Colombian department about 230 km east of Nicaragua and over 700 km from mainland Colombia; the International Court of Justice upheld Colombia's sovereignty in 2012.
Q 16The Cayman Trough marks the Caribbean Plate's boundary with which other tectonic plate?
North American
The Cayman Trough lies along the transform boundary between the North American and Caribbean plates, which slide past each other at about two centimetres a year.
Q 17The Caribbean Sea is estimated to be how old?
160 to 180 million years
The Caribbean Sea is thought to be 160 to 180 million years old, formed when a horizontal fracture split the supercontinent Pangaea during the Mesozoic Era.
Q 18Pressure from which tectonic plate to the east gives the Lesser Antilles their volcanic activity?
The South American
The South American Plate, subducting westward beneath the Caribbean Plate, fuels the Lesser Antilles volcanic arc; Mount Pelée's 1902 eruption on Martinique killed about 28,000 people.
Q 19Kick 'em Jenny, an active submarine volcano, lies 8 km north of which island?
Grenada
Kick 'em Jenny, an active submarine volcano whose summit lies under 200 metres below the surface, sits about 8 km north of Grenada; its first recorded eruption sent steam 275 metres into the air.
Q 20In which year was Kick 'em Jenny first recorded erupting, generating two-metre tsunamis on nearby coasts?
1939
Kick 'em Jenny's first recorded eruption came in July 1939, breaking the surface and sending waves about two metres high onto Grenada's north coast and the southern Grenadines; the name earlier referred to a nearby rock.
The North Equatorial Current, entering from the tropical Atlantic, is the principal current; with the warm, moist easterly trade winds it produces climates from rainforest to semi-arid around the sea.
Q 24Which warm current runs northwest along South America's coast to feed the Caribbean Current?
The Guiana Current
The Guiana Current flows northwest along the coasts of Brazil and the Guianas, carrying South Equatorial Current water into the Caribbean Sea, where it merges with North Equatorial flow to form the Caribbean Current.
Q 25Cool upwelling keeps which islands arid?
Aruba, Bonaire and Curaçao
Aruba, Bonaire and Curaçao, the ABC islands off Venezuela, are arid partly because trade-wind-driven upwelling of cool water along South America's coast suppresses rainfall; each averages under 600 mm a year.
Q 26The Caribbean hurricane season runs during which months?
June to November
The Atlantic hurricane season officially runs from 1 June to 30 November, and most Caribbean hurricanes strike in August and September.
Q 27Per the National Hurricane Center, how many hurricanes struck the Caribbean from 1494 to 1900?
385
The National Hurricane Center counts 385 hurricanes in the Caribbean between 1494 and 1900; most form off West Africa and track west across the Atlantic, while some develop within the sea itself.
Q 28The Caribbean is home to roughly what share of the world's coral reefs?
About 9%
About 9% of the world's coral reefs lie in the Caribbean, covering roughly 50,000 square kilometres, mostly around the islands and along the Central American coast.
Q 29Coral bleaching happens when warm water kills off which symbiotic organisms living inside coral polyps?
Zooxanthellae
Zooxanthellae, single-celled algae living in coral tissue, supply most of the coral's food and its colour; when water warms, corals expel them and turn white.
Q 30The Cartagena Convention protecting the Wider Caribbean's marine environment was adopted in which year?
1983
The Cartagena Convention was adopted on 24 March 1983 in Cartagena, Colombia, and entered into force in 1986; its three protocols cover oil spills, protected areas and land-based pollution.