[bkor]

> Is whatever the standard mechanism is for securing containers to ships sufficient here?

Not in the slightest. Containers are secured by lashing them. But that's just the one level, mostly. Then after that it is twist locks. There are enough pictures of containers being ripped apart by the sea. Or stacks entirely damaged. Containers are made from steel, loads of people tend to assume they're indestructible. Or that they can hold way more weight than they can (scrapped metal people).