The Internet of Underwater Things (IoUT) is essential for ocean research, but energy consumption is a major obstacle. Named Data Networking (NDN), with its in-network caching, offers a potential solution for efficient data transmission and reduced energy use in underwater environments. However, NDN’s caching strategy can lead to a low cache hit ratio, high redundancy, resulting in energy waste and performance degradation. This paper proposes a novel caching strategy called Energy-Saving Caching (ESC), based on energy profit. Firstly, the new naming discovery package is used to announce and network the content to surrounding nodes, then the energy profit of the cached data is calculated through the content popularity and hop count information. When the interest arrives, the caching decision is made according to different profit information, aiming to reduce the overall energy consumption of the underwater network. Experimental results demonstrate that the proposed caching strategy effectively decreases the total energy consumption of the underwater network while improving the cache hit ratio and reducing the average retrieval delay.