Know your marine weather hazards
Weather conditions on the coast, ocean, lakes, bays and rivers can change fast.
Each year, marine rescue and life saving organisations respond to thousands of calls for assistance from people on the water. Many of these incidents are caused by or made worse by the weather.
Marine weather hazards impact the marine industry, recreational boaters, kayakers and rock fishers. These hazards include:
- wind, gusts and squalls
- waves and swell
- tides and sea level
- severe weather.
Whether you’re boating, rock fishing or kayaking, our marine weather information will help you stay safe.
Wind, gusts and squalls
Wind, gusts and squalls can make your activities on the water dangerous.
Wind gusts can be:
- 40% stronger than the forecast average wind speed
- more than twice the average wind speed in squalls and thunderstorms.
It's useful to learn about your local wind patterns, as wind speed and direction can be affected by the local environment.
Learn about how wind, gusts and squalls can affect wave conditions in our Marine knowledge centre.
Waves and swell
Large waves and swells can be hazardous, but so can smaller sea and swell waves if they catch you off guard.
In shallower bays, the crests of wind waves (chop) are closer together, which can be hazardous for smaller vessels.
Swells generated by distant weather systems can arrive even when the weather may appear calm. These long period swells can come as a surprise as there can be a long period of calm (lull) between the sets of waves.
This can create unsafe conditions for boaters, rock fishers and swimmers.
Learn about types of waves, wave height and other features on our waves, seas and swell page.
Tides and sea level
Changing tides can create hazards by influencing the behaviour of waves, currents, and water levels. Waves can become unpredictable and steeper.
Key things to know about tides:
- Water levels rise quickest around mid tide.
- Rising tide brings surging waves.
- Tide times change every day and in different locations.
- The weather can change the predicted tide levels.
- When the tidal current and wind direction are in opposite directions, waves can become steeper and closer together.
Tides affect waves and sea levels for bar crossings, rock fishing and boating. Know the tide times for your local area by checking our tide predictions. You'll find this information on our current website – we're still building this new one.
Learn more about tides and sea level in our Marine knowledge centre.
Severe weather and coastal hazards
Severe weather can make conditions unsafe for boating, rock fishing and other marine activities. It can bring hazardous weather and coastal conditions, such as:
- heavy rain with poor visibility
- lightning
- large hail
- floods
- tropical cyclones
- damaging or destructive winds
- storm surge, damaging surf and unpredictable currents.
Learn more about severe weather and coastal hazards in our Severe weather knowledge centre.
About marine forecasts
Our marine forecast services help you plan ahead and stay safe in or on the water.
Marine weather forecasts describe the average conditions for wind, weather, sea and swell. They can't describe in detail all expected conditions in the area over a long period of time.
Be prepared for local effects. Geographical features such as river mouths, cliffs and islands can also influence the wind and waves.
Marine forecast schedule
Local and coastal waters forecasts:
- are issued twice a day around 4 to 5 am/pm local time
- cover 3 to 4 days
- are updated every 6 hours if a wind warning is current
- are updated when conditions change significantly.
High seas forecasts cover the next 24 hours and are updated every 12 hours. Ocean wind warnings are updated every 6 hours.
All forecasts include the time when the next forecast will be issued, and any current wind warnings.
Marine forecast areas
Our forecasts cover:
- local waters – bays, harbours and inland waters where frequent boating activity occurs
- coastal waters – within 60 nautical miles of the coast
- high seas – for broader ocean areas around Australia.
We use land reference points to mark either end of the area covered by each forecast. For example, the Central Gippsland Coastal Waters Forecast: Wilsons Promontory to Lakes Entrance, covers the coastal area from Wilsons Promontory to Lakes Entrance.
Find maps of our forecast and marine radio broadcast areas on our Marine weather service areas page.
Coastal and local waters forecast descriptions
We describe location and time in our coastal forecasts as:
Location:
- Inshore – from the coast out to 12 nautical miles.
- Offshore – from 12 to 60 nautical miles.
Time of day when the forecast conditions are expected to occur:
- Early in the morning – before 7 am.
- In the morning – 1 am to 11 am.
- In the late morning – 9 am to midday.
- During early afternoon – midday to 4 pm.
- During the afternoon – 1 pm to 9 pm.
- In the evening – 6 pm to midnight.
- Later in the evening – after 9 pm.
The forecast direction of the wind and swell is the direction the wind or wave is coming from. This is based on true north orientation.
For example, a northerly wind or swell is travelling from the north towards the south.
Marine wind, wave and weather warnings
Marine warnings alert you to:
- wind conditions
- hazardous or damaging surf
- other types of severe weather.
Marine wind warnings
We issue marine wind warnings for local and coastal waters:
- for winds 26 knots or stronger
- up to 42 hours in advance or anytime conditions develop rapidly
- whenever strong winds, gales, storm force or hurricane force winds are forecast.
Warnings are updated every 6 hours or as conditions change. If conditions ease, the warning will be cancelled.
Ocean wind warnings
Ocean wind warnings are for mariners involved in commerce and travel on ocean-going vessels in the Australian high seas regions.
View the Ocean wind warning areas map on our Marine weather service areas page to check which areas are covered.
Ocean wind warnings are:
- issued whenever gale, storm or hurricane force winds are expected
- provided up to 24 hours in advance
- updated every 6 hours or as conditions change significantly.
The warning will include the issue time and key information, such as:
- the warning statement – for example, 'Gale warning for Western Area'
- a description of the weather situation generating the warning conditions
- the boundary of the area affected in latitude and longitude coordinates
- forecast details for the affected area, including wind speed and direction, seas and swell.
For current Ocean wind warnings check our Warnings and alerts page.
Understanding wind warnings
There are 5 key details you need to know about wind warnings to help you decide:
- if it's safe to go out
- whether to change your plans – the time, day or area of your voyage
- if you should turn around and head back
- to take precautions and seek shelter.
Wave, swell and surf warnings
We issue 2 types of warnings about larger waves.
Hazardous Surf Warning
The Hazardous Surf Warning is for rock fishers, boaters and swimmers at risk from large swells and waves.
We issue hazardous surf warnings for:
- New South Wales and southern Queensland
- hazardous surf conditions occurring today or tomorrow, up to 42 hours in advance.
Warnings will be cancelled if the conditions ease.
The criteria for hazardous surf is based on wave height, swell direction, and swell period.
When a hazardous surf warning is issued, a caution statement is included in the:
- Coastal Waters forecasts
- coastal district, town and city forecasts.
Coastal Hazard Warning – Damaging Surf
This warning is for communities vulnerable to large waves that may:
- cause coastal erosion
- damage coastal infrastructure
- break over the top of sea walls (wave overtopping), or
- have other impacts.
Learn more about our severe weather and coastal hazard warning services.
Weather warnings for other hazards
We issue warnings for other weather hazards that may affect activities on oceans, lakes and rivers, including:
- floods
- tropical cyclones
- heavy rain which may lead to localised flash flooding
- abnormally high tides which are likely to cause localised coastal flooding
- damaging winds – sustained winds of gale force or stronger (63 km/h or more) or wind gusts 90 km/h or stronger
- severe thunderstorms which may bring damaging wind gusts, large hail, tornadoes and flash flooding.
Monitor the warnings we issue and how close they are to your activity. Be prepared to change your plans.