A flexible lifting tether system for lifting a marine vehicle or object is described which is capable of significantly improving the primary characteristics of an existing cable by enhancing load-carrying capabilities (e.g. in air), modifying the tether to have altered specific gravities in water, and relieving torsional stresses when in operation.

A signal buoy (1) for retrieval of submerged objects, the signal buoy line's cross section has an aspect ratio greater than two and two tenths to one and preferably greater than four to one. In some aspect the signal buoy line includes conductors so as to permit communicating with submerged objects. In other aspects, the present disclosure teaches a combination of a signal buoy and a buoyant fiber mooring rope storage structure for storing submerged in a body of water and above a seabed or other bottom of the body of water a fiber mooring rope for future retrieval.

The invention notably relates to a water surface autonomous vessel having a hull and configured to be connected, through a lead-in cable having a negative buoyancy, to an end of a seismic cable having a neutral buoyancy and adapted for midwater data acquisition, wherein the water surface autonomous vessel comprises a winch for varying the deployed length of the lead-in cable, and the hull of the autonomous vessel forms a conduct at the back of the autonomous vessel in the direction of deployment of the lead-in cable. This provides an improved solution for seismic prospecting in aquatic mediums.

A signal buoy (1) for retrieval of submerged objects, the signal buoy line's cross section has an aspect ratio greater than two and two tenths to one and preferably greater than four to one. In some aspect the signal buoy line includes conductors so as to permit communicating with submerged objects. In other aspects, the present disclosure teaches a combination of a signal buoy and a buoyant fiber mooring rope storage structure for storing submerged in a body of water and above a seabed or other bottom of the body of water a fiber mooring rope for future retrieval.

An autonomous underwater vehicle (AUV) including a deployable anchor and a method for operating an AUV having a deployable anchor in a hover mode.

The invention notably relates to a water surface autonomous vessel having a hull and configured to be connected, through a lead-in cable having a negative buoyancy, to an end of a seismic cable having a neutral buoyancy and adapted for midwater data acquisition, wherein the water surface autonomous vessel comprises a winch for varying the deployed length of the lead-in cable, and the hull of the autonomous vessel forms a conduct at the back of the autonomous vessel in the direction of deployment of the lead-in cable.

This provides an improved solution for seismic prospecting in aquatic mediums.