In the Argonautic legend, his abode was the island of Drepane (Apoll.
A hero Nauplius took part in the Argonautic expedition; another was king of Euboea.
He destroyed sundry sea-monsters, set free the bound Prometheus, took part in the Argonautic voyage and the Calydonian boar hunt, made war against Augeas, and against Nestor and the Pylians, and restored Tyndareus to the sovereignty of Lacedaemon.
He was the leader of the Argonautic expedition (see Argonauts).
Kirchhoff argues that the Artacia of the Argonautic story must have been taken from the real Artacia, and the Artacia of the Odyssey again from that of the Argonautic story.
He was a great friend of Jason, and took part in the Calydonian boar-hunt and the Argonautic expedition.
In the Argonautic story this fountain is placed in the neighbourhood of Cyzicus, and answers to an actual fountain known in historical times.
A collection of oracles, a theogony, an epic poem on the Argonautic expedition, prose works on purifications and sacrifices, and a cosmogony, were attributed to him.
Or it may be that the Artacia of the Odyssey suggested the name to the colonists of Cyzicus, whence it was adopted into the later versions of the Argonautic story.
Acastus was represented with his famous horses in the painting of the Argonautic expedition by Micon in the temple of the Dioscuri at Athens.