The present invention relates broadly to an unmanned surface vessel (10) comprising a hull (12), an underwater appendage (14), a winch (16), and a cable or rope (18). The cable or rope (18) is at its distal end attached to a remote device (20) with the cable or rope (18) arranged to cooperate with the winch (16) to be deployed and retrieved from the vessel (10) via operation of the winch (16). The underwater appendage is in the form of a keel including a cavity (22) designed to partly locate the winch (16).

The present invention relates broadly to an unmanned surface vessel (10) comprising a hull (12), an underwater appendage (14), a winch (16), and a cable or rope (18). The cable or rope (18) is at its distal end attached to a remote device (20) with the cable or rope (18) arranged to cooperate with the winch (16) to be deployed and retrieved from the vessel (10) via operation of the winch (16). The underwater appendage is in the form of a keel including a cavity (22) designed to partly locate the winch (16).

A skeg mounts from the stern of a towing vessel and extends below the waterline. A channel in the skeg protects cables for steamers and a source (e.g., air gun array) of a seismic system deployed from the vessel. Tow points on the skeg lie below the water's surface and connect to towlines to support the steamers and the source. A floatation device supports the source and tows below the water's surface to avoid ice floes or other issues encountered at the water's surface. Seismic streamers have head floats supporting the streamers. Each of the floats has adjustable buoyancy preconfigured to counterbalance the weight in water of the towed component that the float supports. Acoustic signals from a transceiver at the vessel find locations of the towed components. A towed fish at a lower level than the towed components also uses acoustic signals with a transceiver to further refine the locations of the towed components.

A skeg mounts from the stern of a towing vessel and extends below the waterline. A channel in the skeg protects cables for steamers and a source (e.g., air gun array) of a seismic system deployed from the vessel. Tow points on the skeg lie below the water's surface and connect to towlines to support the steamers and the source. A floatation device supports the source and tows below the water's surface to avoid ice floes or other issues encountered at the water's surface. Seismic streamers have head floats supporting the streamers. Each of the floats has adjustable buoyancy preconfigured to counterbalance the weight in water of the towed component that the float supports. Acoustic signals from a transceiver at the vessel find locations of the towed components. A towed fish at a lower level than the towed components also uses acoustic signals with a transceiver to further refine the locations of the towed components.

A sailing vessel is disclosed which comprises a hull, a keel depending from the hull and a mast. A ballast bulb is provided at the lower end of the keel. A first control mechanisms is provided for rotating the ballast bulb about a transverse axis to change the angle of attack of the bulb. A second control mechanism is provided for rotating the bulb about a longitudinal axis of the vessel.

A sailing vessel is disclosed which comprises a hull, a keel depending from the hull and a mast. A ballast bulb is provided at the lower end of the keel. A first control mechanisms is provided for rotating the ballast bulb about a transverse axis to change the angle of attack of the bulb. A second control mechanism is provided for rotating the bulb about a longitudinal axis of the vessel.

A skeg mounts from the stern of a towing vessel and extends below the waterline. A channel in the skeg protects cables for steamers and a source of a seismic system deployed from the vessel. Tow points on the skeg lie below the water's surface and connect to towlines to support the steamers and source. A floatation device supports the source and tows below the water's surface to avoid ice floes. The streamers can have vehicles deployed thereon for controlling a position on the streamer. To facilitate locating the streamers, these vehicles on the streamers can be brought to the surface when clear of ice floes so that GPS readings can be obtained and communicated to a control system. After obtaining readings, the vehicles can be floated back under the surface. Deploying, using, and retrieving the system accounts for ice at the surface in icy regions. In addition, handling the seismic record can account for noise generated by ice impact events.

A skeg mounts from the stern of a towing vessel and extends below the waterline. A channel in the skeg protects cables for steamers and a source of a seismic system deployed from the vessel. Tow points on the skeg lie below the water's surface and connect to towlines to support the steamers and source. A floatation device supports the source and tows below the water's surface to avoid ice floes. The streamers can have vehicles deployed thereon for controlling a position on the streamer. To facilitate locating the streamers, these vehicles on the streamers can be brought to the surface when clear of ice floes so that GPS readings can be obtained and communicated to a control system. After obtaining readings, the vehicles can be floated back under the surface. Deploying, using, and retrieving the system accounts for ice at the surface in icy regions. In addition, handling the seismic record can account for noise generated by ice impact events.

The invention relates to a method for producing or designing a leading edge of a lifting structure, wherein starting at the midpoint of the base (0,0), a curve is applied to the profile of the structure, the length L.sub.1 of which is according to the maximum thickness of the NACA section in the base of the profile H.sub.0 in the base and is defined by the equation L.sub.1=0.0510H.sub.0.sup.20.0790H.sub.0+15.5790, and the maximum height of which on the x-axis is located at point L.sub.1/2 and defined by means of the relationship x=0.0137(L.sub.1).sup.1.4944, the shape of said curve being defined by means of the equation: (yy.sub.0)=0.0000000107x.sup.6+0.0000016382x.sup.50.0000794412x.sup.4+0.0010194142x.sup.3+0.0097205322x.sup.2+0.0136993913x, and the rest of the curve being calculated by means of an iterative process according to the above.

A keel guard is comprised of a strip of PVC material having a length and a width. An alignment section is positioned along the length of the strip that is visible through the PVC material. The alignment section, which may be a groove for engaging the keel, facilitates installation and enables the installer to maintain the desired straightness along the entire installed length. Additionally, the see-through PVC material reveals any trapped air bubbles between the keel guard and the hull, enabling the are bubbles to be more easily removed, thereby providing a stronger, more uniform bond.