How can a ship in fall down in sea?

Answer 1

I presume you mean 'sink' or 'capsize'.

A ship sinks when it becomes heavier than the water it displaces.

Put another way, The length and breadth of a ship, pushes an amount of water away, which weighs exactly the same as the ship.

Keep adding weight and the vessel will sink lower, until the topsides of the vessel become submerged and allow more water to fill the inside.

The weight is now more than the shape of the vessel can push away and it sinks.

Capsizing, is when the weights inside the vessel (or external pressure such as wind) are more to one side than the other. If the sides become submerged and allow water in, the vessel may sink. (as above)

Poor stability will also cause capsizing. Simply put, a vessel will stay upright as long as the lower part is heavier than the top part. If this is reversed, by loading weights too high up, the vessel will turn over.

That's why you should never stand up in a small boat.

Answer 2

A ship can sink at sea due to reasons such as hitting an underwater object, taking on water from a leak or breach, or encountering extreme weather conditions like storms or hurricanes that cause the ship to capsize or become overwhelmed by waves. Additionally, errors in navigation, equipment failure, or lack of proper maintenance can also contribute to a ship sinking.