(πηδάλιον, Acts 27:20, strictly a footlet; "helm," James 3:4), an oar (hence the English paddle) used by the ancients for steering vessels, being passed through an eye or rowlock at the stern; when at anchor they were unshipped, and secured from slipping through the rudder port by lashings (ζευκτήρια, "bands"). There were usually two of these rudders (hence the plural), one on each quarter of the vessel. (See SHIP).

Bibliography Information
McClintock, John. Strong, James. Entry for 'Rudder'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. https://www.studylight.org/encyclopedias/eng/tce/r/rudder.html. Harper & Brothers. New York. 1870.

Bible Encyclopedias Rudder

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

Bible Encyclopedias
Rudder