Trierarch is a set of free wargames rules for ancient naval warfare. The author writes:
TRIERARCH is an ancient naval warfare simulation based on the most recent information I’ve been able to gather on the performance of the Athenian trireme, as it was used in the battles against the Persians and the Peloponessian war.
The modern reconstruction of the Athenian trireme developed over the past two decades is nothing like the old Hollywood version of the ancient oared warship, and quite different from the Mediterranean galleys of more recent times. It is a lightweight, agile, highly efficient rowing machine, more like a scaled-up racing shell than a gigantic rowboat. The rowers made up a significant fraction of the weight of a trireme, giving it tremendous acceleration, able to reach enough speed to deliver a solid ram from a standing start in a matter of seconds. A well-trained rowing crew could spin a trireme in its own length by rowing forward on one side and backward on the other, making the trireme extremely maneuverable.
TRIERARCH attempts to use this model of the trireme to focus on the performance of individual ships in combat. It has more in common with an aerial dogfight simulation than with most other naval simulations. The game scale is 25 meters per hex and four seconds per turn. Units are individual triremes; each counter takes up two hexes. Movement is unplotted and simultaneous, with each trireme constantly able to respond to the motions of its opponents.