Driving Through Salt Water? King Tides and Your Wheels

The flood that shows up on a sunny day

You know the scene. Blue sky, no rain in the forecast, and a stretch of Las Olas or A1A under several inches of water anyway. Drivers slow down, look at each other, and roll through.

That's a king tide. The water isn't rain. It's the ocean, pushing up through storm drains and over low spots. And that means it's salt water, which is a different problem for a car than an afternoon downpour.

What a king tide actually is

King tide isn't a scientific term. NOAA calls it a popular, non-scientific name for an exceptionally high tide. The astronomy behind it: when a new or full moon lines up with the moon at perigee, its closest point to Earth, tides run higher than usual. NOAA's tides and currents FAQ (opens in a new tab) says these "perigean spring tides" happen six to eight times a year.

The flooding they cause has an official name too. NOAA calls it high tide flooding, also known as sunny-day or nuisance flooding: ocean water that covers low-lying areas at high tide, spilling onto streets or bubbling up from storm drains. NOAA says it's happening more often every year as sea levels rise.

In Broward, it clusters in the fall. The City of Fort Lauderdale posts the season's predicted king tide dates on its King Tides page. Two things to know about those dates:

• They're predictions from tide tables. Wind and rain can push the water higher than forecast, or keep it lower.
• High water usually peaks around high tide, so the same street can be passable a few hours later. If you can wait it out, wait it out.

Why salt water is harder on your car

Rain is fresh water. Tidal floodwater is salt water, and salt speeds up corrosion.

AAA's advice on flood-damaged cars draws the line clearly: a car damaged by fresh water has a better chance of being repaired than one damaged by salt water, because salt is highly corrosive to both the interior and the mechanical parts.

A drive through a few inches of tidal water isn't the same as a car sitting in a flood. But the parts that meet the splash are the parts that live closest to the road:

• wheels and lug hardware
• brake components
• suspension parts
• the whole underside of the car

NHTSA has made the same point about salt in another context. In a 2015 safety advisory about brake-line corrosion from winter road salt, it urged drivers to wash the underside of their vehicles to remove salt and to have brake lines inspected for corrosion. Salt is salt, whether it came from a snowplow or Port Everglades.

Before you drive through it

The best tide-day strategy is not to drive through it at all.

The National Weather Service's Turn Around Don't Drown guidance is blunt: 12 inches of rushing water can carry away most cars, and 2 feet can carry away SUVs and trucks. You also can't see what's under the surface. A road can be damaged beneath standing water with no sign from above.

Practical options on a king tide morning:

• Check the tide and local alerts before you leave if your route runs near the Intracoastal or the beach.
• Detour to higher streets, even if it costs you ten minutes.
• Wait for the tide to fall when the trip can move.
• If you truly can't tell how deep it is, turn around.

Already drove through it? The rinse routine

If you went through salt water, do this soon after:

1. Rinse the underside. A car wash with an underbody spray or a garden hose aimed under the car both work. Get the wheel wells.
2. Rinse the wheels and brakes. Spray through the wheel spokes, not just the face of the wheel.
3. Rinse again if you drove through it more than once, or on several days during the tide cycle.

That's it. You're not trying to detail the car, just get the salt off before it sits.

A tide-day routine for people who live near the water

If you live or park east of US-1 or along the Intracoastal, a few habits help during the fall king tides:

None of this is complicated. It just works better as a routine than as a scramble on the morning the street floods.

Signs it's time to have it inspected

Watch the car for the next week or two. Have a technician take a look if you notice:

• New brake noise, like grinding or squealing that wasn't there before
• A pull to one side when braking or driving straight
• A new vibration through the steering wheel or seat
• A TPMS light that comes on and stays on (our TPMS light guide explains what it means)
• Water inside the car. That's no longer a splash. Treat it as a flooded vehicle and don't drive it until it's been checked. Our post on what to check after a car sits in floodwater covers that case.

Extreme Tires in Sunrise does brake repair and alignments in the shop, and tire rotations, balancing and TPMS service at the shop or by mobile van in the local install area. If something feels off after tide season, call (954) 773-1896 and ask, or book an appointment.

And if the rest of your storm-season prep is still on the list, our hurricane car prep checklist starts with the tires.