Aquaplaning: What It Is and How to Avoid It

Driving in heavy rain can be challenging enough, but one of the most dangerous hazards on wet roads is aquaplaning, also known as hydroplaning. It’s a sudden and frightening loss of control that happens when your tyres lose contact with the road surface. Understanding what causes aquaplaning—and how to prevent it—can keep you and others safe in wet conditions.

Fast Facts

• Regularly check tyre pressure and keep all four tyres properly inflated.

• Maintain tyre tread depth above the legal minimum of 1.6 mm.

• In rainy conditions, slow down and increase your braking distance.

• Avoid worn or mismatched tyres that reduce water displacement.

What Is Aquaplaning?

Aquaplaning occurs when a layer of water builds up between your tyres and the road surface. At high speeds, the tread pattern can no longer push water aside fast enough. The result? Your tyres lose grip, and the vehicle effectively floats on top of the water.

When this happens, your steering, braking, and acceleration become unresponsive—leaving you with almost no control over your car.

Aquaplaning is most common:

• During heavy rainfall or immediately after a downpour

• On uneven roads where puddles collect

• When tyres are underinflated or worn out

How to Reduce the Risk of Aquaplaning

There are several practical steps every driver can take to prevent aquaplaning:

1. Check Tyre Pressure Regularly

Ensure your tyres are inflated to the manufacturer’s recommended pressure. Underinflated tyres have less effective contact with the road and are more prone to aquaplaning.

2. Maintain Proper Tread Depth

Tyre tread plays a crucial role in channeling water away from the tyre.

• The legal minimum tread depth is 1.6 mm, but experts recommend replacing tyres at 3 mm for optimal safety.

• Worn tyres dramatically reduce water displacement and increase stopping distances.

3. Slow Down in the Rain

Reducing your speed gives your tyres more time to clear water. Even a small decrease in speed can significantly reduce the risk of losing traction.

4. Replace Tyres Before They’re Worn Out

Don’t wait until your tyres hit the legal limit. Replace them early to maintain maximum performance and safety—especially before the wet season.

Tread Depth: Why It Matters

Even at low speeds, insufficient tread depth can increase the risk of accidents.

New tyres can disperse up to 30 litres of water per second at 80 km/h (49 mph). But as the tread wears, this ability decreases dramatically.

• At 1.6 mm tread depth, water displacement is severely reduced.

• At 3 mm, tyres still maintain much of their water-clearing ability, but beyond that, the risk of hydroplaning rises sharply.

Braking Distance Example (Contidrom Test)

• 8 mm tread (new tyres): Standard braking distance.

• 3 mm tread: +2.7 metres longer to stop.

• 1.6 mm tread: +6.9 metres longer to stop.

Even a few extra metres can be the difference between a near miss and a collision.

Tread Depth Indicators

Modern tyres include Tread Wear Indicators (TWIs) — small raised bars inside the tread grooves. When the surrounding tread wears down to the same level as these bars, it’s time to replace your tyres.

Many tyres also feature “wet indicators” at 3 mm, serving as an early warning before performance drops significantly.

For best results:

• Check tread depth regularly using a depth gauge.

• Replace tyres before reaching the minimum depth.

• Fit tyres with matching tread patterns on each axle to maintain consistent performance.

What to Do If Your Car Starts to Aquaplane

Even with the best precautions, aquaplaning can still happen. If it does:

1. Ease off the accelerator immediately.

2. Depress the clutch (in manual cars) to disengage power.

3. Do not brake or steer suddenly—this can worsen the skid.

4. Once you feel your tyres regain contact with the road, gently steer and continue at a reduced speed.

If a collision seems imminent, use emergency braking—rear tyres often retain enough grip to help slow the car safely.

Key Takeaway

Aquaplaning happens in seconds but can be avoided with good tyre maintenance and cautious driving. Keep your tyres in top condition, slow down in the rain, and always give yourself extra time and distance.

When it comes to safety, the road beneath your tyres is only as secure as the tread that grips it.