Cumulonimbus or thunderstorm clouds (see diagram) produce strong, gusty winds that blow out from the front of the storm. If you see this type of cloud, you should watch which way it is moving – clouds often move in different directions from the wind at the surface. If it looks like it will pass over or within a few kilometres of you, head for shore immediately.

Safety hints

• Ensure you are carrying the prescribed safety equipment.
  
• Ensure you wear a lifejacket where required and consider wearing a lifejacket at all times while operating a vessel.
  
• Know the local factors that influence sea conditions and know where shelter can be reached quickly.
  
• Learn how to read the weather map.
  
• Be aware that the weather map in the morning newspaper was drawn the day before.
  
• Always check the latest forecast and warnings before going to sea and know what conditions exceed your safety limits.
  
• Beware of rapidly darkening and lowering cloud – squalls may be imminent.
  
• When at sea, listen to the weather reports on public or marine radio.
  
• Be flexible – change your plans if necessary.
  
• Be prepared to head back to shore regardless of how far you have travelled.
  
• Be prepared for changes in conditions and take warm clothing.