Seismic reservoir monitoring has been found to be effective with recent ocean-bottom seismic techniques. The technology of ocean-bottom nodes can be extended to a semipermanent ocean-bottom-node (SPN) acquisition type, which is fixed on the seabed and activated on demand for reservoir monitoring. A newly developed SPN method allows a high-speed underwater optical to communicate with a remotely operated vehicle or an autonomous underwater vehicle to stably harvest seismic data on multiple repeat surveys. Long-term capabilities of deployment life, cumulative recording time, and internal clock characteristics are also key technologies for practical use of SPN acquisition. This is an alternative to fixed ocean-bottom cables that are currently a major tool of permanent reservoir monitoring. SPN acquisition will present more flexibility for receiver spreads, low installation cost, and fewer risks for asset management compared with existing seabed technologies.