The Stormiest Seas In The World

Post by: Dee White
29 March 2016

Places to avoid if you like safe sailing

Bay of Biscay

This gulf, tucked in between the French and Spanish borders is home to the Atlantic’s fiercest weather. Its unique position attracts powerful winds and the shallow sea bed produces heavy wave motion. As winter begins and weather worsens, depressions cause severe weather at sea and constant rain along the shores.  Sometimes powerful windstorms form if the pressure falls rapidly, travelling along the Gulf Stream at great speed, resembling a hurricane and finally crashing in the bay with their maximum power. There is also the phenomenon of June Gloom, a large fog triangle which can fill the southern half of the bay.

(Lubeck D in the Bay of Biscay – Isaac Newton Feb 1975, Wikimedia Commons)

The area’s unpredictability has resulted in many a merchant vessel floundering on its way from the UK to the Mediterranean or the Canaries. Square riggers had problems being unable to make way to windward after having been driven into the Bay and often ports became inaccessible because of the rapid build up of Atlantic Swell. Modern yachts, with their more efficient rigs and the help of good weather forecasting, should not have quite the same problems, but there have nevertheless been several occasions of yachts getting into difficulties with sometimes fatal consequences.

Cook Strait, between North & South Islands of New Zealand

Cook Strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southwest. It is 22 kilometres wide at its narrowest point and is considered to be one of the most dangerous and unpredictable waters in the world. It is subject to belts of strong wind that circle the globe around 40 degrees south, known as the Roaring Forties. These produce large waves and the Cook Strait “wind tunnel” effect, which means that the tide elevation at the ends of the strait are out of phase with one another, resulting in a boat being pelted by high water on one side and low water on the other. Although the tidal surge should flow in each direction for six hours, a particular surge might last eight or ten hours, followed by a feeble reverse surge. In particularly bad weather the reverse surge can be nil resulting in a flow remaining in the same direction through three surge periods or longer. The ocean flow is further complicated by submarine ridges running off from the coast. A southerly gale can blow up a big swell very quickly and there is a phenomenon called the Kaori Rip, a patch of unnatural water where the wind and seas meet the tide head-on. That is when boats can have a rough trip.

(Wikimedia Commons)

The strait is named after James Cook, the first European commander to sail through it in 1770. It was the scene of two of New Zealand’s worst maritime catastrophes; the Penguin disaster in 1909 and the sinking of the ferry Wahine in 1968.

Drake Passage, Southern tip of South America

This is one of the world’s most renowned stormy seas, also known as the “Sea of Hoces”. The 800 km wide passage is the shortest crossing from Antartica to the rest of the world, connecting the Atlantic and Pacific oceans between Cape Horn and the South Shetland Islands. With no large landmass anywhere at the latitudes of the Drake Passage there is an unimpeded flow of current carrying a huge volume of water through it. This, together with the region’s naturally high wind speeds, frequently rough waters and risk of icebergs, ensures its stormy reputation.

(Antarctic iceberg – Gregory “Slobirdr” Smith, Wikimedia Commons)

Though bearing the name of the famous English seaman Sir Francis Drake, whose ship was blown far south after passing through the Strait of Magellan, the passage was first traversed in 1616 by a Flemish expedition led by Willem Schouten.

It used to be considered the most dangerous ship passage in the world, sailing vessels taking weeks just to round the Horn and even today, rounding Cape Horn is still considered a major accomplishment by today’s sailors. Violent, chaotic, notorious and unpredictable are all words used to describe this sea passage in which over 20,000 sailors have lost their lives.

(HMS Endymion rounding the Horn – Drawing by Herbert Roxby, Wikimedia Commons)

Irminger Sea, between southern Greenland & Iceland

The Irminger Sea is situated south of the Denmark Strait which separates Iceland from the east coast of Greenland by 250 miles of rough water. It is thought to be the windiest stretch of salt water on the globe and one of the stormiest places in the world. Ocean scientists have been studying the Irminger for the last 10 years. Hampered by its storms, powerful complex currents and convoluted seafloor topography, much about the sea remains unknown. Interestingly the sea is a narrow passage on the doorstep of the Arctic Circle and is a bottleneck on the “superhighway” of the oceans’ global circulation. It is the main route for waters flowing south from the Arctic Ocean to the North Atlantic Ocean.

(Explorer of the sea waves – Bing Images – whoi.edu)

Maracaibo Lake, Venezuela

This large, brackish lake or bay is the largest lake in South America, at 13,210 square kilometres. Storms develop over the northern part of this lake on about 140-160 nights a year, providing extraordinary lightning displays. The famous “Catatumbo Lightning” phenomenon is named after the river that flows into the lake and where the storms are most frequent. It is a nearly continuous thunderstorm with up to 20,000 flashes of lightning per night and lasting approximately 10 hours long. It produces 10% of tropospheric ozone in the world.

(Catatumbo lightning, Lake Maracaibo – Ruzhugo27, Wikipedia)

There are several theories explaining the continuous storms. The high winds sweeping across the lake crash into the cool air spilling down from the Andes, forcing it upward as thunder clouds. Another factor could be the boggy marshes which release methane gas.

The lightning phenomenon has become a part of the tales of the indigenous people of the area and a huge draw to tourists who now come on special trips to watch the natural display. The local fishermen profit from the light display as they are able to navigate at night without any problem.

Port George lV, Western Australia

Australia’s stormiest location is on the shores of the Timor Sea where 100 thunderstorm days a year is the norm. Beneath the sea lie considerable reserves of oil and gas, resulting in a number of offshore petroleum projects and considerable exploration activity. With so many storms and cyclones passing through the area oil and gas production are often interrupted. Although petroleum production facilities are designed to withstand the effects of cyclones, production is often reduced as a safety precaution and workers are sometimes evacuated to the mainland.

(Oil spill from Montara offshore oil platform in the Timor Sea – DLR, Wikimedia Commons)

South China Sea

The weather in this part of the Pacific Ocean is tropical and largely controlled by monsoons. Tropical typhoons and cyclones are also frequent and have caused some serious disasters in the area. What makes it even more dangerous is the “Dangerous Ground”, a large area of low islands, sunken reefs and barely covered atolls. The annual rainfall varies from about 2,000mm to 3,000mm around the southern basin. The area is poorly chartered and rife with territorial disputes making it an area best avoided at all costs.

(Satellite picture of the South China Sea – Serglo – from NASA World Wind Globe, Wikimedia Commons)

Southern Ocean

The Southern Ocean, also known as the Antarctic Ocean or the Austral Ocean, circles round Antarctica and comprises the southern-most parts of the world’s oceans. It is where cold, northward flowing waters from the Antarctic mix with warmer subantarctic waters. It is subject to frequent huge swells, many rough seas and the frequently occurring threat of icebergs at any time of year. Some may have drafts of several hundred meters, but even smaller ones, together with iceberg fragments and sea ice, also pose problems for ships. The fact that it is less well travelled and documented than any other ocean makes it even more hazardous and its remoteness makes sources of search and rescue scarce.

(Antarctic Blue – Christopher Michel, Wikimedia Commons)

Lake Victoria, Uganda, Africa

(Sail on Victoria Lake, Uganda – Damiano Luchetti, Wikipedia)

The north of this lake is the area that experiences the most thunderstorm days in the world. In Kampala thunder is heard on an average of 242 days of the year. This is caused by the convergence of land-breeze over the lake during the night, releasing instability of the moist lower layers of air and the development of cumulonimbus clouds and thunderstorms over the lake.

The massive lake straddles three East African countries, Uganda, Tanzania and Kenya; it stretches some 70,000 square kilometres and is the world’s second largest freshwater body. It provides a livelihood for the many fishermen navigating its waters and the businesses lining its shores, but with that livelihood comes a great risk. It is believed that about 5,000 people are killed every year on the lake, victims of the erratic weather conditions and a mix of poor communications and lack of resources. This makes the lake arguably the most dangerous stretch of water in the world in terms of fatalities per square kilometre.

Those using the lake are hoping that a new mobile alert system aiming to improve the delivery of weather forecasts, will give more guidance on what kind of storms to expect ever the lake and what action they should take.