A close up view of one of the 68lb solid shot cannons used for coastal defence between 1880 and 1900. These are more extensively described in shot 12761.

I don't think that the cargo ships out to see have much to worry about.

Addendum: My personal opinion is that Facebook and all other members of the Meta group are disgusting, sociopathic organisations that steal other peoples' intellectual property (including the images in this gallery) despite being explicitly denied permission to do so.