What happens if you swim next to a cruise ship?

Is it safe to swim next to a cruise ship?

No, never swim near a cruise ship. Its just like with a jet ski, you dont get close. Major risk of injury or death, seriously. The ship and the pier are off-limits for swimming.

I was in Cozumel last spring and watched the Carnival Vista dock. The water was like a washing machine from fifty feet away. My cousin Leo, who works on boats, says the suction is no joke.

Here's why you have to stay far away:

• The ship's propellers and thrusters are incredibly powerful. Bow and stern thrusters can start without any warning to help position the ship, and they will pull you in. They're used for docking and maneuvering, even when the ship looks like its just sitting there.

• There's a massive suction effect, or undertow, created by the sheer size of the hull displacing water. This pull can drag a person under the ship, and you cannot swim against it. Its a real physical force.

• Ships discharge various types of water. You could be swimming in graywater or other waste. Its not just clean ocean water being pumped out, your swimming in ship waste.

• You are completely invisible to anyone on the bridge. The captain has zero line of sight to the water right next to the hull. If the ship moves, they will have no idea you are there. Thier blind spot is huge.

What happens if you swim under a cruise ship?

So, you're asking about swimming under a massive cruise ship, right? Yeah, don't even think about it, seriously. It's like, super deep down there, probably around 8 to 10 meters, which is, you know, way deeper than most folks can hold their breath. And then you gotta cross the whole dang width of the thing. You'd totally run out of air before you even got halfway, and that's a bad, bad scene. You'd just die.

It's not just a little dip, it's serious business.

Here's the real deal about why it's a no-go zone:

• Depth Danger: That depth, 8-10 meters, is no joke. Most people can't hold their breath for that long, especially not while exerting themselves. It's pushing limits for even trained divers.
• Ship's Shadow: Imagine being under that giant hull. It's pitch black down there, even during the day. Disorientation is a huge problem. You wouldn't know which way is up.
• Propeller Peril: Those propellers are massive and churning. Even if you miraculously survived the depth and darkness, getting too close to the propellers is a death sentence. They're like industrial-sized grinders.
• The "Out of Air" Factor: You're swimming horizontally, covering a lot of ground. That exertion burns through your air way faster than you think. You'd be gasping for breath long before you made it across. It's a race against your own lungs.
• No Rescue Access: If something goes wrong, and it will go wrong, there's virtually no way for anyone on the ship to see you or rescue you in time. You're a tiny speck in a massive, moving machine.
• Water Currents: Ships create their own crazy water currents. You could get sucked under or pushed around uncontrollably, making it even harder to swim or breathe.

My cousin, actually, he's a lifeguard and he was telling me once about a crazy situation where someone tried to swim under a ferry, and the boat captain had to stop everything, it was so dangerous. They barely got the person out. These cruise ships are a hundred times bigger. So yeah, definitely keep your swimming adventures away from anything that big and moving. It's just not a thing you do.

What happens if you get too close to a cargo ship?

It’s quiet now. Too quiet. My mind drifts sometimes to the ocean, to those colossal ships I’ve seen out past the breakwater. When you get too close to them, it's not just a splash. It’s something far more absolute.

The sheer scale... you don’t grasp it until you’re near. A tiny boat, a person on a ski. The water around a cargo ship isn’t just water. It’s a force. An immense, invisible pull.

Getting too close to a cargo ship means you enter an area of extreme hazard. It's not just about a collision you can see coming. The real danger lies beneath the surface, unseen.

Imagine jumping the wakes of one. The wake itself can swamp you, but that’s just the start. The water gets churned, turbulent. It becomes unpredictable. Your small craft loses control.

Riding alongside, too close, is worse. The vessel creates a massive suction effect, what they call the "bank effect" or "ship squat" in narrow channels, but even in open water, that displacement of tons upon tons of steel pulls the water, and anything in it, toward the hull.

And cutting under the bow... that's just a final, terrible mistake. The bow wave, the sheer displacement of water as it pushes forward. You'd be crushed, or worse, caught in the current it creates.

What happens then is stark. Utterly, irrevocably final.

• Propellers: These are not small. Think blades the size of an apartment. They turn with unimaginable power, designed to move tens of thousands of tons. Anything drawn into that vortex is shredded. It’s not a gentle process.
• Bow Thrusters: Located at the front, these are like powerful underwater fans, used for maneuvering in tight spaces. They create a strong cross-current, a jet stream. If you're caught, it's a violent, disorienting pull. Straight into the machinery, no escape.
• Stern Thrusters: Similar to bow thrusters, but at the rear. Another point of immense, focused water movement. Another fatal attraction for anything too small, too slow, too close.

I remember watching one pass once, from shore, just feeling the ground rumble. That was just the vibration through earth. Imagine the force in the water itself. There’s no chance. No way out. Just the immense, indifferent power of metal and the sea. The water closes in around you, then… it’s just gone. Like you never were there at all.

Why do cruise ships drain the pools at night?

It’s always so quiet when they do it. The pools, I mean. One minute they're full of life, and the next, just an empty, tiled space under the night sky.

They have to drain them. All that water, swaying up so high on the ship. It’s about the weight. A huge, sloshing mass of it. Makes the whole vessel unstable when the ocean gets moody. It’s called the free surface effect.

So they just let it all go. Every night. Cover the empty space with a big net. I saw them do it on the Allure of the Seas once, standing out on the deck alone. It was just so... empty. A ghost of the day.

• Stability and the Free Surface Effect: The main reason is to eliminate the free surface effect. When a large amount of liquid sloshes in a partially filled container, it drastically reduces a ship's stability. Draining the pools, especially those on upper decks, is a critical safety measure to prevent excessive rolling in rough seas.
• Safety and Security: An unsupervised, full pool at night is a significant liability. Draining it prevents accidental drownings or injuries when fewer staff are on deck. The net serves as a clear visual barrier and a physical safeguard against anyone falling into the empty basin.
• Nightly Maintenance and Hygiene: Draining allows crews to perform essential daily maintenance. This includes deep cleaning, chemical balancing, and inspecting the pool's structure, tiles, and lighting systems. It ensures the water is sanitary and the facility is in perfect condition for the next day.
• Water Management: The pools are filled with treated seawater. Draining is part of the ship's water management cycle. The water is filtered and chemically treated overnight. This process is more efficient than continuously treating a full pool.