Systems and methods of deploying seismic data acquisition units from a marine vessel are disclosed. The system can include a spindle coupled to a tether. A robotic arm can couple the spindle to a tether via one or more tumblers. The tether can connect to a seismic data acquisition unit via a connection block having a mechanical force device. The assembled spindle, tether and seismic data acquisition unit can be deployed from the deck via a deployment block.