Hazards, warnings and safety

Rough water image

Each year marine rescue and life saving organisations respond to thousands of calls for assistance from people in trouble along the coastline, on the ocean, or on inland waterways. Many of these incidents are caused by or made worse by the weather. Understanding the impact of weather hazards can help you be better prepared, or change your plans for safer conditions.


Find out about the key weather hazards to marine and land-based water activities, and our recommended weather safety checks for some of the most common activities.

Weather hazards

The Bureau issues warnings for winds over 26 knots. Marine wind warnings are issued for coastal and local waters areas whenever strong winds, gales, storm force or hurricane force winds are expected. The six things you need to know about wind warnings will help you understand how to get the most from these warnings.

It is useful to learn about your local wind regimes, as these can make conditions rough in certain areas. One example is the Southerly Buster along Australia's east coast.

A squall is an abrupt and large increase in wind speed that usually only lasts for minutes then diminishes rather suddenly. The gusts in a squall may exceed 40 or 50 knots and boaters should avoid these situations.

Wind gusts are typically 40% stronger than the average wind speeds provided in marine forecasts. However, thunderstorms and squalls may produce much higher gusts.

Large waves originate from intense weather systems. These waves can be higher, steeper and more chaotic than usual, especially close to the coast where the waves enter shallower water. Wave recording buoys provide near real-time wave information in most states, and the Bureau's marine forecasts include information about expected wave heights.

Long period swells are typically generated by low-pressure weather systems. These swells can travel for days and many hundreds of kilometres from where they were formed. While they're in deep water, these long, low swells are not a problem, but as they approach shallow water they break powerfully. Because the systems that generate these waves can be far off the coast, these waves can come as a surprise since it could be sunny with little wind when they arrive.

The Bureau provides a range of services that provide information about waves. You can check the seas and swell section of the coastal waters forecast or look at the wave forecasts in MetEye. Wave forecasts for larger ocean areas, including wave period, are available in the Bureau's weather and wave map.

Warnings about larger waves are available for Hazardous Surf (targeted at swimmers, boaters and rock fishers), Damaging and Dangerous Surf (targeted at communities vulnerable to the effects of larger waves, for example coastal erosion).

Tropical cyclones pose a significant danger to mariners due to huge waves, extreme winds, thunderstorms and torrential rain with poor visibility. Find out more about tropical cyclones.

Thunderstorms can generate strong, squally winds, heavy rain with reduced visibility, hail, waterspouts and lightning. They are common across the Australian region and can pose a threat to mariners. Coastal Waters forecasts and MetEye provide information about the likelihood of thunderstorms. When thunderstorms are forecast for capital city Local Waters areas, it is important to check if Severe Thunderstorm Warnings have been issued.

East Coast Lows are intense low-pressure systems which occur on average several times each year off the eastern coast of Australia, in particular southern Queensland, NSW and eastern Victoria. These storms can produce heavy rainfall, gale to storm force winds, powerful waves and storm surges. Find out more about East Coast Lows.

Cold Fronts can cause strong to gale force winds, gusty conditions around the front, thunderstorms, hail and heavy rain and showers. Cold fronts are boundaries between a warm and cold air mass. Winds are usually northerly before the front then westerly or southerly behind the front.

The Monsoon is a large scale rain and wind event experienced in the tropics during the wet season. It can persist for multiple days and is associated with the inflow of moist west to northwesterly winds into the monsoon trough, producing convective cloud and heavy rainfall over northern Australia. Find out more about Monsoon.

Sea Fog can be extensive and long-lasting, presenting a significant hazard to mariners. Visibility can reduce to less than 100 metres in sea fog, making navigation difficult and greatly increasing the risk of collision with obstacles or other vessels.

Waterspouts are spinning columns of air and water. They can be very dangerous, much like the hazardous tornadoes seen over land. Read more about waterspouts.

Weather safety checks

The Bureau has advice for a range of marine and water-based activities, so you can know your weather and know your risk, and get access to the best tools to help you plan ahead.

Before heading out boating, use the Bureau’s marine forecasts and warnings and run through the five vital weather safety checks to be prepared.

Going boating?  Do the five vital weather safety checks

Check your local or state maritime authority and also the Australia New Zealand Safe Boating Education Group website for boating safety information.

The Australia New Zealand Safe Boating Education Group recommends that boaters change their plans, delay their journey, or cancel their trip if weather or wave conditions exceed the limits of their vessels capability or risk the safety of crew and passengers.

Marine warnings


The Bureau of Meteorology issues a range of warnings for marine areas when dangerous winds and waves are expected.

For more information about each warning service, see:

Changing weather


Take note of forecasts indicating reduced visibility from fog or rain, or risks to safety and comfort from thunderstorms, lightning or squall conditions.

Some forecasts will also include information on UV levels and the times of day to use sun protection.

All coastal and local waters forecasts can be accessed from the Marine & Ocean webpage.

Boating during thunderstorms is dangerous

Wind conditions


Winds of any speed can be hazardous for boating. Know the limits of your vessel and your abilities. A typical rule of thumb is for small craft to avoid winds greater than 15 knots.

Marine wind warnings are issued whenever strong winds, gales, storm force or hurricane force winds are expected. The six things you need to know about wind warnings will help you understand how to get these warnings, and what to do when they are issued.

Wave conditions


It is important to know what wave conditions are forecast, as waves can make your boating trip dangerous and uncomfortable - especially close to the coast where the waves enter shallower water.

Tide times


Knowing when high and low tide will occur is important for boats entering and exiting river entrances and crossing bars. The combination of an outgoing tidal flow or low tide can cause waves to become steeper than usual, making your boat difficult to navigate.

The changing tide over the day can cover rock platforms or reefs at high tide, whilst exposing them and creating a hazard at low tide.

See our five vital weather safety checks for rock fishing here.

See our five vital safety checks for paddling here.

See our weather safety advice for offshore sailing and yacht racing here.

See our weather safety advice for surfing here.

See our weather safety advice for domestic commercial vessels here.



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