Laudator Temporis Acti

Mark Kurlansky, Cod: A Biography of the Fish That Changed the World (New York: Penguin Books, 1997), p. 165:

After the effectiveness of the trawl wire cutter was demonstrated, the second Cod War degenerated into dodgem cars on the high seas. Trawlers attempted to prevent Coast Guard vessels from cutting their trawl by ramming them. But the Coast Guard vessels could also ram, and their reinforced hulls, built for icebreaking, made them particularly effective at this.

Ramming in the cod wars was a reversion to a more ancient form of naval warfare, except that the ancient form was more deadly. Ancient warships were equipped with a sharp bronze-clad "ram" on the prow at or below the waterline. With this ram, sailors tried to puncture the hull of enemy ships, and then withdraw. Aeschylus, Persians 408-409, describing the Battle of Salamis, says, "Immediately ship against ship dashed its bronze-clad beak" (εὐθὺς δὲ ναῦς ἐν νηὶ χαλκήρη στόλον / ἔπαισεν).

Lionel Casson, The Ancient Mariners (Minerva Press, 1959), pp. 100-101, describes the skill and endurance involved, both in attack and defense:

Ramming was a most delicate maneuver. Only a skilled crew and a commander of fine judgment and keen sense of timing could bring it off. For one thing, it was a one-shot or at best a two-shot affair. A captain couldn't afford to miss more than twice, for by then his rowers were too exhausted to go through the grueling procedure all over again. At the moment of impact his ship had to be travelling at an intermediate speed: if too slow, the enemy could back water out of range; if too fast the thrust would embed the ram too deeply in the enemy hull and his men couldn't back water in time before the opponent's marines could grapple and board. If the first thrust missed or wasn't mortal, his men had to be ready to back water at full speed just enough to get into proper position again and then resume forward motion at the appropriate ramming speed. It was this need to fight a battle in a sort of slow motion as it were that made marines an essential part of the complement of all vessels, even those designed chiefly for the use of the ram. Without such fighters to rake the opponent's deck during the approach or to stand by to repel boarders after the impact, the attacked vessel's marines could grapple, board, and stand a fair chance of taking over the attacker. Themistocles used fourteen spearsmen and four archers per ship at Salamis; fifty years later Athenian admirals were able to cut the spearsmen to ten.

Those navies which, because of the slowness of their vessels or the poor quality of their crews, could not depend on the ram were forced to rely more on marines. In battle their captains' prime concern was to avoid destruction from a ram stroke, and the standard method of accomplishing this was to keep, at all costs, the prow toward the enemy and give him no chance to get at the flanks or stern. If a captain could do this successfully -- it most often involved constant and careful backing water -- until the enemy crews were exhausted, he could then bring the fight down to one between marines, in which the advantage lay on his side. If he could destroy enough enemy personnel in this phase, he might be in a position to attack with the ram himself or, failing that, to grapple and board.

One of the most spectacular archaeological discoveries in recent years was the 1980 discovery of the so-called Athlit Ram, a bronze ram from a Hellenistic warship, 465 kg. in weight and 2.26 m. in length, on display at the National Maritime Museum in Haifa, Israel. See here and here for photos.

A Greek bronze coin (here and here) from Arados in Phoenicia (162/1 B.C. = Sylloge Nummorum Graecorum, The Danish National Museum, Copenhagen, 36cf) shows a three-pronged naval ram.

Our English word rostrum is related to this technique of ancient naval warfare. See the Online Etymology Dictionary, s.v. rostrum:

1542, from L. rostrum, name of the platform stand for public speakers in the Forum in ancient Rome. It was decorated with the beaks of ships taken in the first naval victory of the Roman republic, over Antium, in 338 B.C.E., and the word's older sense is "end of a ship's prow," lit. "beak, muzzle, snout," originally "means of gnawing," instrument noun form of rodere "to gnaw" (see rodent). Cf. claustrum "lock, bar," from claudere "to shut." Extended sense of any platform for public speaking is first recorded 1766. Plural form is rostra.