In the north the Spanish at first found an able naval leader in Admiral Bossu, himself a Hollander, who for a time kept the coast clear of Beggars. In October, 1573, however, 30 of his ships were beaten in the Zuyder Zee by 25 under Dirkzoon, who captured five of the Spanish vessels and scattered the rest with the exception of the flagship. The latter, a 32-gun ship terrifyingly named the _Inquisition_ and much stronger than any of the others on either side, held out from three o'clock in the afternoon until the next morning. Three patriot vessels closed in on her, attacking with the vicious weapons of the period--pitch, boiling oil, and molten lead. By morning the four combatants had drifted ashore in a tangled mass. When Bossu at last surrendered, 300 men, out of 382 in his ship's complement, were dead or disabled. Though not yet able to stand up against Spanish infantry, the Dutch in naval battles were usually successful. In the Scheldt, January 29, 1574, 75 Spanish vessels were attacked by 64 Dutch under Admiral Boisot. After a single broadside, the two fleets grappled, and in a two-hour fight at close quarters eight of the Spanish ships were captured, seven destroyed, and 1200 Spaniards killed. The Spanish commander, Julian Romero, escaped through a port-hole, is said to have remarked afterwards, "I told you I was a land fighter and no sailor; give me a hundred fleets and I would fare no better." In September following, Admiral Boisot brought some of his victorious ships and sailors to the relief of Leyden, whose inhabitants and garrison had been reduced by siege to the very last extremities. The campaign that followed was typical of this amphibious war. Boisot's force, with those already an the scene, numbered about 2500, equipped with some 200 shallow-draft boats and row-barges mounting an average of ten guns each. Among them was the curious _Ark of Delft_, with shot-proof bulwarks and paddle-wheels turned by a crank. As a result of ruthless flooding of the country, ten of the fifteen miles between Leyden and the outer dyke were easily passed; but five miles from the city ran the Landscheidung or inner dyke, which was above water, and beyond this an intricate system of canals and flooded polders, with forts and villages held by a Spanish force four times as strong. The most savage fighting on decks, dykes, and bridges marked every step forward; the Dutch in their native element attacking with cutlass, boathook and harpoon, while the superior military discipline of the Spanish could not come in play. But at least 20 inches of water were necessary to float the Dutch vessels, and it was not until October 3 that a spring tide and a heavy northwest gale made it possible to reach the city walls. In storm and darkness, terrified by the rising waters, the Spanish fled. The relief of the city marked a turning-point in the history of the revolt.