Marine radios are a great way to get assistance when you're more than 2 nautical miles form the shore.

Mayday - the whole vessel is in grave and immediate danger

Pan Pan - an urgent signal to indicate that you require assistance but there is no immediate danger.

For example, you've run out of fuel and will hit the rocks in many hours time. you need fuel urgently but you'll live. This would be 'pan pan'.

However if you've run out of fuel close to the dangerous rocks and will impact them in a few minutes, you would use a 'mayday' call.

Securite - a safety signal to indicate an issue such as log in the river or a weather warning

You must carry a waterproof torch onboard a powered vessel (except PWC) at all times, regardless of location or time of day.

Your torch must be buoyant and waterproof.

All vessels must have a sound signalling device such as a horn or a whistle.

Sound signals are often used by large vessels to indicate their manoeuvring intentions.

For example, the Manly ferry when about to reverse out of Circular Quay will communicate this to other vessels with three short blasts of their horn to raise awareness to other vessels in the vicinity.

Reverse, three short blasts. 

You only have a limited number of flares onboard, there's no point wasting them when no-one is around to see them.

Keep your eyes and ears peeled for signs of other boats and planes. When there's a chance of your flares being seen, ignite them to alert them to your emergency.

Marine radios must be carried onboard when boating more than 2 nautical miles from the shore.

They are used to signal for emergency assistance, get important weather updates and more.

We've also made a helpful study video about this.

Sound signalling devices are used to indicate your position and communicate with other vessels.

These are typically airhorns, whistles or bells.

You must carry a sound signalling device onboard at all times on powered vessels (except PWC).