Maritime activities are always risky. Weather is one of several factors that cause maritime work and recreation to be risky and dangerous, but forecasting the weather can help prevent accidents that lead to shipping and cargo losses, injuries, and even fatalities.
Weather can be difficult to predict, especially on waterways, but good forecasting can help ships and their crews navigate and make decisions that reduce risks. Bad weather can cause ships to capsize, to run aground, or to collide with other ships or objects. Knowing what kind of weather is coming is extremely important in making maritime activities safe.
Weather at sea is not the same as weather over land. The main driving forces are winds, including the trade winds, which blow to the west in the tropical oceans, and the westerlies, which blow to the east in the mid-latitude regions. Winds create surface ocean currents by dragging across the water. In the northern hemisphere, these currents move in clockwise rotations while in the southern hemisphere, they move in counterclockwise rotations.There are also smaller currents that move along the edges of the major currents, called gyres. The smaller, boundary currents are numerous and include the Gulf Stream, which moves from the Gulf of Mexico, along the eastern coast of the U.S. and Canada, and across the ocean to the British Isles. These currents generate and influence much of the maritime weather that we see across the world’s oceans.
Weather generates waves and swells, which have a big impact on vessels. Winds produce waves in the oceans, and the size of the waves depends on the strength and duration of winds and how far the winds blow without interruption. Swells are groups of large waves that outrun the wind or storm that generated them. Ships at sea may also face rogue waves, unusually large waves among smaller waves. These can cause a lot of damage.
Waves and winds occurring together during storms are particularly dangerous and include hurricanes, also called typhoons and cyclones. These are very large and damaging storms. They are high-speed winds rotating around a calm center, called an eye. Predicting the formation, strength, duration, and path of a hurricane is an important part of maritime forecasting.
Maritime weather can be unpredictable, and this is why forecasting is so important. Forecasting isn’t perfect, but it does give navigators and other crew the ability to make better decisions about routes. Shifting cargo, equipment falls and overboard accidents can all result from rough weather and listing ships.
Ships can also get blown off course by severe weather, which can lead to serious accidents. These include running aground in shallow waters or on reefs, which can damage ships, throw crew members overboard, and even cause a ship to sink. Weather can even cause a ship to run into another ship or an object like a bridge, which can cause similar accidents.
