Tributary Tomcat Tandem Inflatable Kayak with 2 seats. The Tributary Tomcat Tandem by AIRE is a durable, 12'6" (3.81 m) inflatable kayak designed for whitewater and recreational paddling, priced around $1,200. Featuring a 500 lb (227 kg) capacity, 3-chamber design, and self-bailing floor, it is suitable for two people or solo paddling with extra gear. Key features include 1000-denier PVC construction, adjustable thwart seats, and Summit II valves.