'Iako Construction
The ʻiako of the waʻa kaukahi (single-hulled canoe) were traditionally made from hau. Prior to European contact, canoe builders recognized two primary varieties: hau koʻiʻi and hau kaekae (often referred to simply as hau).
Hau koʻiʻi is distinguished by its rougher bark and, at times, a faint reddish cast to its leaves. Its flowers mature into dry seed pods that remain attached to the branches even after drying. This variety is notably denser and does not lighten as much when seasoned.
Hau kaekae, by contrast, has smoother bark, lacks the reddish tinge, and does not retain the dry seed pods. It dries lighter and is more buoyant. For this reason, hau kaekae was generally preferred for both the ama and the ʻiako.
In selecting hau for ʻiako, size and proportion are critical. For a waʻa kaukahi in the range of 20–40 feet, the ʻiako should not be less than 2½ inches in diameter, with 3 inches being ideal. For a waʻa kaulua (double-hulled canoe), the ʻiako should be no less than 3½ inches, with 4 inches preferred. Strength must be balanced with lightness; the ʻiako carries load but must not burden the canoe.
Finding the right piece of hau is not done from the ground. It requires climbing into the branches of the hau forest, where the natural curves of the wood can be properly seen. As Arnold Nathaniel was known to say, “you can’t find good ʻiako standing on the ground.” From within the canopy, one can read the lines of the tree—where it bends, where it holds straight, and where it carries its strength. He also pointed out that this practice reflects a broader truth: one must step beyond comfort, understand the risks, and move with care to find what is truly valuable.
The ideal ʻiako for a waʻa kaukahi lies straight across the wae (also referred to as kua ʻako), then rises slightly along the lapuʻuna before descending toward the ama at the kapuaʻi. This upward lift—often no more than an inch—is purposeful. It allows waves passing between the kaʻele (hull) and ama to move through without striking the ʻiako in rough water.
At the kapuaʻi, the ʻiako is often notched to seat securely against the rounded surface of the ama. A small peg, or pou, may be set into the kapuaʻi to help hold the lanalana lashing in place, preventing it from slipping free under strain.
Once harvested, the bark is stripped away and the inner cambium layer—soft and slick—is scraped clean. The ʻiako is then, when possible, soaked in salt water for several days. This practice helps deter insects and prolongs the life of the wood.
There are also accounts of shaping ʻiako through the use of heat, possibly by steaming in a long imu to make the wood more pliable. While details of this process are not well documented, it suggests a deeper knowledge of working with the natural flexibility of hau to achieve the desired form.