Battle of Rhium

The Battle of Rhium (429 BC) or the battle of Chalcis was a naval battle in the Peloponnesian War between an Athenian fleet commanded by Phormio and a Peloponnesian fleet composed of contingents from various states, each with its own commander. The battle came about when the Peloponnesian fleet, numbering 47 triremes, attempted to cross over to the northern shore of the Gulf of Patras to attack Acarnania in support of an offensive in northwestern Greece; Phormio's fleet attacked the Peloponnesians while they were making the crossing.

• http://en.wikipedia.org/wiki/Battle of Rhium