A fellow redditor made a curious comment on this topic:
Hammer Heads are scary, ugh.
They were actually considered by the Greeks as a method of controlling trade routes. An example is how the Greeks would try to round up all of the Hammer Heads into the Strait of Gibraltar during wartime.
This alone wouldn't detour their enemies from trying to pass trading ships through, but one of their top Ship Captains at one time named Acacius had outfitted his ship with a bronze 'ramming plate' for lack of a better term, and he would run his ship into enemy ships to cause them to begin to sink. (This is before Cannons were common place or efficient on ships)
The panic among the sailors - sinking in water filled with hammer heads - was unbelievable. Eventually most sailors would outright refuse to approach the Strait, and the Greeks controlled the entire Mediterranean for hundreds of years until one of the major big-box department stores of the 1990s finally made a deal with them to allow traffic back through.
Anyhow, that's probably why the Hammerhead is attacking this Kayak.
Link here
So is it true? Did the Greeks really do this?
Not really sure how the rules apply to this situation...but that's a novelty account and pretty clearly a joke post. Gibraltar is nowhere near Greece and he says things like:
the Greeks controlled the entire Mediterranean for hundreds of years until one of the major big-box department stores of the 1990s finally made a deal with them to allow traffic back through.
Day to day though, the Strait of Gibraltar did offer better nightlife than Athens around that time, so a lot of Greeks would head over there on a Friday night for some Corona and a bit if Fish n Chips.