Location Transport - how often does shipping containers fall off cargo ships to the bottom of the sea?

how often does shipping containers fall off cargo ships to the bottom of the sea?

Not very often..it really depends on the weather the ship is travelling through.
Quite often and they float just under the water> Some sink if heavy enough>
Quite often, but not in European waters. The real danger is that many of them don't sink, and present a real hazard to small ships.
5 times a day
Containers falling off of ships is not unusual. I've known many people who have hit or came unnervingly close to unseen floating containers. There are all kinds of strange things floating around in the ocean. I have repaired a number of boats that have hit mystery things. Some of the claims are likely false. A few Captains egos won't accept the fact that they err... same with carpenters or doctors or whatever. We will never know how many there are at the bottom of the sea. Never.
It happens more often than you might think it would. Not all of the container ships are the huge ones. But, even the large ones have containers swept overboard by waves. Smaller ones, fairly frequently. Rogue waves also claim containers. I have never seen a total loss for any time period, but there are shots of this happening on U-tube. One other thing, they do not always sink and present a hazard to ships as they can sink very slowly, and float awash for a long time. A small ship or yacht can do itself great damage to hit one. Fortunately, the ocean is very large and the chances are small. Regards, Dan PS Check out the website listed below. It may interest you.