Conductive gels have been developing vigorously as superior wearable sensing materials due to their intrinsic conductivity, softness, stretchability and biocompatibility, showing a great potential in many aspects of our lives. However, compared to their wide application on land, it is significant yet rather challenging for traditional conductive gels to realize sensing application under water. The swelling of gels and the loss of conductive components in the aqueous environment, resulted from the diffusion across the interface, lead to structural instability and sensing performance decline. Fortunately, great efforts have been devoted to improving the water resistance of conductive gels and employing them in the field of underwater wearable sensing in recent years, and some exciting achievements have been obtained, which are of great significance for promoting the safety and efficiency of underwater activities. However, there has been no review to thoroughly summarize the underwater sensing application of conductive gels. This review presents a brief overview of the representative design strategies for developing water-resistant conductive gels and their diversified applications in the underwater sensing field as wearable sensors. Finally, the ongoing challenges for further developing water-resistant conductive gels for underwater wearable sensing are also discussed along with recommendations for the future.