Adsorption refrigeration is an effective way to use low-grade energy sources such as industrial waste heat without damaging the environment. A novel exhaust-driven adsorption icemaker on a fishing boat is introduced in this paper. Based on the previous study, combining with the single adsorption cooling tube technique, this paper presents an adsorption cooling unit with unique structure driven by exhaust waste heat (hereinafter referred to as "waste heat cooling tube" WHCT). Different with the previous tubular structured adsorption bed, WHCT is made of seamless stainless steel pipe, the adsorbent bed, evaporator / condenser are all placed in one tube. Adsorption working pair of calcium chloride-ammonia has been proposed and developed for adsorption cooling. The working principle and structure are introduced in this paper.