The dimensions of the Viracocha rafts I and II were 18 meters long, 4.75 meters wide at the center or beam and weighed a total of 20 tons. The Viracocha III will be built with virtually the same same dimensions of the two preceding expeditions.
2.5 million reeds for each raft are needed, which are harvested on the shores of Titicaca lake, Bolivia and Peru, where reed grows in abundance. The reed is cut with a long stick with a knife at one end, usually from a row boat and then are tied in bundles with about 500 in each. These are bought to land and sun-dried for two or four weeks. The Bundles are stacked in standing position. After drying, the reed are collected and stored carefully to prevent damage from rain. The reed is usually 2cm thick at the base (before compressed) and 2m long.
The reed, then it is converted into more than 30 long cylinders or roles of 50 centimeters in diameter, which will be the length of the raft. This will form the main body of the ship. The template or base is then constructed, which serves as a mold. It is built with eucalyptus logs.
Two smaller ships are built, to add rigidity to the raft with the same technique used to manufacture the main hull. These are placed side by side on top of the mold. The cylinders are located at the top of the small ships until two separate bundles are formed.
The "Estera" or skin of the boat is the next phase and is made by weaving the best stock of the reeds making the length of the boat. This skin is wrapped around the two large bundles. A heart, or third bundle is placed in the center of the much larger bundles. Two strands of sisal rope, each 2250 feet in length is than passed around one large bundle and around the heart in one foot revolutions for the entire length. The same is done on the other side. Never does the rope wrap around the whole ship.
Attaching the two large bundles that form the gunnels or "sawi" is the last step of the hull construction. Rope is wound around each gunnel and passed through each main bundle rope along the length of the ship. The rigging is attached here and the gunnels help break the larger waves.
The rope tightening is next. A pulley system is used to haul on the boats to get them gradually tighter. There are only two long continuous ropes, 2,250 feet on either side. The pulling begins on one end and is hauled on until taut.
The ropes are pulled roughly thirty more times on each side, shrinking the size of the boat each time. This ingenious design now consists of two large bundles linked together by a heart that has now disappeared into the larger two bundles forming a stable, almost double hulled vessel.
The double stern adds more stability and carrying capacity to the ship while at sea The next phase is to build up the bow and stern. Tapering cones of reeds are wedged together until a high bow and double stern are formed.
The crew and volunteers constructed the rest of the vessel. Two bipod of masts were positioned on either side of a bamboo cabin for Viracocha I and a third smaller mast was utilized further aft for the Viracocha II. The masts were held in place by "shoes" roped into the bundles. Two rudder oars were lashed to a steering platform placed above and to the rear of the bamboo cabin. The ship was rigged with natural fiber sisal rope, the same rope that holds the reed bundles together. Two center boards were positioned in the slide boxes placed in the fore and aft of the ship and aided in the tacking into the wind. Several lee-boards were placed on the lee-side of the ship and were removable. Two cotton Lateen sails were hand sewn for the first journey and four sails were used for the second.
Two rudder oars were attached to a steering platform placed above and to the rear of the bamboo cabin. The raft was handled with sisal natural fiber rope holding the same reed packages together. Two tables were placed on the side boxes at the bow and stern of the raft, which help in tacking into the wind. Various removable boards or "guaras" were placed on the leeward side of the raft. Two cotton sails Lateen style were handmade for the first trip and 4 sails were used for the second.