Tethys-Plantgeria Limited is a Nigerian marine and diving contracting company specializing in underwater engineering, subsea operations, and offshore construction for the oil and gas and maritime industries. Its services include commercial diving, underwater inspection, maintenance and repair (IMR), remotely operated vehicle (ROV) services, subsea pipeline installation and repairs, geophysical and geotechnical surveys, non-destructive testing (NDT), tanker loading terminal maintenance, vessel chartering, marine transportation, and subsea installation and construction. The company also provides marine project support, focusing on operational safety, technical expertise, and reliable offshore solutions.