[manarth]

The BBC can unfortunately often be light on details for articles such as this.

Heritage Daily has an article with more details, undersea mapping, photos, and cites the source (the International Journal of Nautical Archeaology).

https://www.heritagedaily.com/2025/12/network-of-submerged-s...

[teruakohatu]

That is a much better article.

It is not a wall, but rather a “network of submerged stone structures”.