I'm trying to visualize the sailing conditions the Phoenicians would have faced at Bojador - and not really succeeding, because I don't know enough about their vessels.
But I'm sure the challenge would be different, and potentially less scary, from Henry the Navigator's bane. The Portuguese were in high-freeboard open-ocean sailing carracks, with no effective recourse to rowing. And Bojador, coming from the north, presents a terrifying lee shore: the winds and current push vessels towards it, with shoals extending from the coast. Sailing close to a lee shore is a bit like walking on a slack line: one mistake and disaster is inevitable. You need to accurately predict your drift over the whole transit, you need hope the wind doesn't veer, and because there's a ferocious current too, the wind must not die. In short, it takes a skilled captain and navigator (and the much better strategy is just to sail offshore, which is what the Portuguese eventually did). Even a modern Bermudan yacht would be challenged attempting to transit Bojador southerly and close to shore.
A Phoenician trireme-type-boat would not be able to sail upwind at all - rowing would have been required for this part of the journey. Maybe on a lull day they could out-row the current? In any case, the challenges were different - and they would have had the additional motivation of not being able to turn back for home.
[0] Source: I'm a sailor!
Footnotes so formatted are a shibboleth of this community, not a practicality.
Also, Hanno the Navigator's journey is slightly better attested and includes traversing the cape north and south. Here is a commented translation of the account, from a Phoenician temple by way of Greek translators: https://www.livius.org/articles/person/hanno-1-the-navigator...
I agree - I don't think it's as big of a challenge as the above commenter thinks.
Phoenician boats would have been significantly shallower drafts, and more importantly, they would have been sailing with the wind and current, not against it, since they were coming north at that point, not going south.
But I'm sure the challenge would be different, and potentially less scary, from Henry the Navigator's bane. The Portuguese were in high-freeboard open-ocean sailing carracks, with no effective recourse to rowing. And Bojador, coming from the north, presents a terrifying lee shore: the winds and current push vessels towards it, with shoals extending from the coast. Sailing close to a lee shore is a bit like walking on a slack line: one mistake and disaster is inevitable. You need to accurately predict your drift over the whole transit, you need hope the wind doesn't veer, and because there's a ferocious current too, the wind must not die. In short, it takes a skilled captain and navigator (and the much better strategy is just to sail offshore, which is what the Portuguese eventually did). Even a modern Bermudan yacht would be challenged attempting to transit Bojador southerly and close to shore.
A Phoenician trireme-type-boat would not be able to sail upwind at all - rowing would have been required for this part of the journey. Maybe on a lull day they could out-row the current? In any case, the challenges were different - and they would have had the additional motivation of not being able to turn back for home.
[0] Source: I'm a sailor!
Footnotes so formatted are a shibboleth of this community, not a practicality.