In the following passage from book 5 of the Iliad, Athene and Hera are travelling in their chariot intending to help the Greeks who are being forced back by the Trojans in the battle.
ὅσσον δ᾽ ἠεροειδὲς ἀνὴρ ἴδεν ὀφθαλμοῖσιν
ἥμενος ἐν σκοπιῇ, λεύσσων ἐπὶ οἴνοπα πόντον,
τόσσον ἐπιθρῴσκουσι θεῶν ὑψηχέες ἵπποι.
As far as a man sitting in a lookout post sees into the misty distance with his eyes as he watches over the wine dark sea, so far do the high whinnying horses of the goddesses leap.
I wondered what the man in the lookout post was looking out for and why there should be lookout posts around the coast. Several possibilities occurred to me. Look out posts could have been created to look out for pirates so you could evacuate the town before they came. Piracy, according to Thucydides, was quite a respectable occupation in Homer’s world and presumable quite common. Or someone could have been looking out for a particular ship that he was expecting as for example Aegeus looked out for Theseus’ ship on his return from Crete, but because Theseus forgot to put up the right sail to show he was safe, threw himself into the sea.
Or another possibility that occurred to me was as follows. On the South coast of England near Swanage there is a look out post and probably others along the coast. The object was, in Victorian times, to look out for shoals of sardines. The fishermen could then set out and catch huge quantities of the fish. Today because of overfishing you don’t get the shoals. The Ancient world had similar posts to look out for tuna. Strabo describes one in Italy.
ἔστι δ᾽ ἐν κόλπῳ βουνὸς ὑψηλός, ἐφ᾽ οὗ τὸ κτίσμα: ὑπόκειται δ᾽ Ἡρακλέους λιμὴν καὶ πλησίον λιμνοθάλαττα καὶ παρὰ τὴν ἄκραν τὴν ὑπὲρ τοῦ κόλπου θυννοσκοπεῖον. ἀκολουθεῖ γὰρ ὁ θύννος οὐ τῇ βαλάνῳ μόνον, ἀλλὰ καὶ τῇ πορφύρᾳ παρὰ γῆν, ἀρξάμενος ἀπὸ τῆς ἔξω θαλάττης μέχρι καὶ Σικελίας.
There is a high hill on the gulf, where the settlement is. Below it lies the harbour of Heracles near it is a a salt marsh. At the high point above the gulf is a tuna watching station. For the tuna follows not only the barnacle but also the purple fish along the coast beginning from the Atlantic as far as Sicily.
The last line of the extract from the Iliad above is one of the many lines in Homer that where the sound imitates the action. At the Hups in ὑψηχέες, you can feel the horses lifting their heads up to whinny.