Why do sea vessels keep on colliding?

[Pink]

First two submarines (one was English the other was French) with nuclear on board crashed into each other under the Atlantic Ocean and now two navy vessels collide with a nuclear powered submarine and another ship.

Doesn't the vessels have a radar which can indicate another vessel approaching?

 

[Don'treallycare]

There are no traffic lights in the ocean.

 

[AlexM]

They have sonar, but the goal of these types of ships is not to be detected. More and more ships are crowding into the same area of water, and these accidents are likely to increase.

 

[rusty]

Contributing factor in this case is the high traffic in the narrow gap that is the Strait of Hormuz. These subs are repeatedly in these types of incidents and need to have missions halted, like you said something is wrong.

 

[rusty]

Contributing factor in this case is the high traffic in the narrow gap that is the Strait of Hormuz. These subs are repeatedly in these types of incidents and need to have missions halted, like you said something is wrong.

 

[JLC]

I know!! Just like how can air plans collide when they have so much free air space in the sky..