3 essential things the RNLI wants you to know

Every time I speak to an RNLI volunteer (as a side note – they’re all incredible!), they mention three main things are are vital for anyone swimming in the sea to know.

These are: flags, float to live and what to know about cold water shock.

Let’s have a look at each!

Flags to know

Lifeguards use flags to signal the safest and most dangerous areas for swimming, surfing and other water activities. Understanding them helps you stay safe and avoid getting into difficulty in unpredictable waters.

Red and yellow flag: safe swimming area

When you see red and yellow flags on the beach, the area between them is the safest place to swim or bodyboard. This zone is actively monitored by lifeguards, who will quickly spot if someone needs help.

I recommend choosing a beach patrolled by RNLI lifeguards and stay between these flags if you’re planning to swim.

Black and white flag: surfboards and kayaks only

Black and white chequered flags mark zones where surfboards, stand-up paddleboards, and kayaks are permitted.

Swimming and bodyboarding are not allowed in these areas, as board users can travel quickly and unpredictably and pose a risk to swimmers.

Red flag: no swimming

A red flag means it is dangerous to enter the water under any circumstances.

Strong currents, big surf, or other hazards make swimming life-threatening when this flag is raised. Always respect a red flag warning and stay out of the water completely.

Orange windsock: strong offshore winds

An orange windsock indicates strong offshore winds. These winds can push inflatables like lilos and dinghies far out to sea very quickly. If the windsock is flying, avoid using inflatables and be extra cautious even if you are just paddling near the shore.

What to do if you get into trouble: Float to Live

If you unexpectedly find yourself struggling in the water, your instinct might be to swim hard.

But cold water shock could make you gasp uncontrollably, increasing the risk of breathing in water.

Instead, remember to Float to Live.

To float effectively:

• Tilt your head back with your ears submerged.
• Relax your body and breathe as normally as possible.
• Move your hands gently to help you stay afloat.
• Spread your arms and legs to improve stability.
• It’s fine if your legs sink — everyone’s body floats differently.

Once you have controlled your breathing, you can either call for help or swim to safety if you are able.

How to prevent cold water shock

Cold water shock happens when you enter water below 15°C. It can cause a sudden gasp reflex, rapid breathing, and loss of control over your limbs.

The shock to your body can also increase your heart rate and blood pressure dangerously fast, putting you at risk of cardiac arrest.

The average UK sea temperature is only around 12°C, even in summer.

Inland waters like rivers, lakes, and reservoirs can be colder still.

Knowing how your body reacts to cold water helps you stay calm.

If you fall in, Float to Live to regain control of your breathing before attempting to move or call for help.

Always follow RNLI advice

RNLI lifeguards are highly trained and have a detailed understanding of local conditions. Always follow their instructions and read the safety boards posted at the entrance to lifeguarded beaches. Their advice can change throughout the day as tides and weather shift.

Quick tip

Download local RNLI beach maps or check the information boards at the beach entrance before swimming.

Many beaches also have live updates available through RNLI apps or websites, allowing you to check for red flag warnings, windsock alerts and rip current risks before you even set foot on the sand.

See my list of mistakes often made at UK beaches for more information.