Māori told missionaries during the Musket Wars that battles between waka took place at sea with the aim being to ram an enemy's waka amidships at high speed. The ramming vessel would ride up over the gunwale and either force it under water or cause it to roll over. The enemies were either killed, left to drown or captured to be used in cannibal feasts or as slaves if they were female. This description matches the attack on the ship's boat of Abel Tasman in Golden Bay in 1642 when a Māori catamaran rammed a cock boat and four Dutch sailors were killed. During the classic period (about 1500 to 1770) a "hapū" would select a "totara" tree and prepare it years ahead for felling. "Totara" is a lightweight wood with a high natural oil content that helps prevent rot. This would include the removal of bark from one side of the trunk and the clearing of the ground and the planting of food crops for workers. After chants and prayers the tree would be felled by a combination of fires around the base and chopping with hand adzes. On an especially large tree with aerial roots a stage about 3 m high was built of wood. On this was built a framework on which was suspended a giant upside-down "toki" (axe), about 2.5 m long. The long axis of the "toki" was tied to the crossmember of the upper framework so that it could pivot back and forth, like a swing. Heavy rocks were tied to each side of the long axis at its lowest point to give momentum. The "toki" was pulled back and released so that the cutting edge bit into the wood that was weakened by fire. It could take two to three weeks to cut down a large tree in this manner. The head of the tree and branches were removed, then the hull was roughly shaped "in situ", using fire and hand adzes, under the guidance of the chief designer. A stone adze was used by relatively gentle, but regular and repeated blows. The head was soaked in water to make the binding swell and hold the stone blade more firmly. Once the shaping was complete, the log of 3–4 tonnes was pulled by teams of men to a stream or river, using multiple ropes made from "raupō". Some men pulled the waka forward while others restrained it on downhill slopes. Accidents at this stage were apparently common. Saplings were used as skids and rollers over uneven ground.