Most of the ocean resources, which cover over 70% of the Earth's surface, are not well discovered or explored. For decades, ocean communities have resorted to underwater robotic vehicles (URVs), remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) to replace human beings or manned underwater vehicles (MUVs) on deep underwater activities. Combining the advantages of ROVs and AUVs, a new type of underwater explorer named the hybrid underwater robotic vehicle (HURV) has been developed for both deep-sea exploration and intervention by switching its dual-operation modes for accomplishing underwater tasks during one single cruise deployment. This paper presents an overview of the state-of-the-art URV system, where the HURV system is the main concern. The concept of the HURV is introduced via a comparison with other underwater vehicles, after which the thinking behind the HURV design is examined and the operational procedure of the HURV is described. Subsequently, the specifications and capabilities of typical HURVs worldwide are presented and the latest developments in HURV technology in the Mainland China is explored in detail. Finally, future technology trends and unforeseen potential applications of the HURV system are also discussed.