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 boat with a foam material filled keel structure comprising: a buoyant body, which is a U-shaped tube; a bottom plate, set on the bottom of the buoyant body; a tail plate, set at the rear of the buoyant body and the bottom plate; and a keel structure, set on the bottom of the bottom plate; wherein the keel structure is downward depressed, hence a convex part on the bottom and a groove on the top are formed; wherein in the groove of the keel structure is filled with foam material, Thereby it is achieved that water seepage in the keel structure is avoided.

A boat with a foam material filled keel structure comprising: a buoyant body, which is a U-shaped tube; a bottom plate, set on the bottom of the buoyant body; a tail plate, set at the rear of the buoyant body and the bottom plate; and a keel structure, set on the bottom of the bottom plate; wherein the keel structure is downward depressed, hence a convex part on the bottom and a groove on the top are formed; wherein in the groove of the keel structure is filled with foam material, Thereby it is achieved that water seepage in the keel structure is avoided.

A boat with a foam material filled keel structure comprising: a buoyant body, which is a U-shaped tube; a bottom plate, set on the bottom of the buoyant body; a tail plate, set at the rear of the buoyant body and the bottom plate; and a keel structure, set on the bottom of the bottom plate; wherein the keel structure is downward depressed, hence a convex part on the bottom and a groove on the top are formed; wherein in the groove of the keel structure is filled with foam material, Thereby it is achieved that water seepage in the keel structure is avoided.

A boat with a foam material filled keel structure comprising: a buoyant body, which is a U-shaped tube; a bottom plate, set on the bottom of the buoyant body; a tail plate, set at the rear of the buoyant body and the bottom plate; and a keel structure, set on the bottom of the bottom plate; wherein the keel structure is downward depressed, hence a convex part on the bottom and a groove on the top are formed; wherein in the groove of the keel structure is filled with foam material, Thereby it is achieved that water seepage in the keel structure is avoided.

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 watercraft has a deck; central, left and right pods connected to a bottom of the deck; and a helm assembly disposed on the deck. The central pod is laterally centered relative to the deck. The central pod has a central hull defining a central tunnel, a motor connected to and disposed at least in part in the central hull, and a jet propulsion system disposed at least in part in the tunnel and operatively connected to the motor. The left pod is disposed at a left of the central pod and is laterally spaced from the central pod. The left pod has a left hull that is narrower than the central hull. The right pod is disposed at a right of the central pod and is laterally spaced from the central pod. The right pod has a right hull that is narrower than the central hull.

A watercraft has a deck; central, left and right pods connected to a bottom of the deck; and a helm assembly disposed on the deck. The central pod is laterally centered relative to the deck. The central pod has a central hull defining a central tunnel, a motor connected to and disposed at least in part in the central hull, and a jet propulsion system disposed at least in part in the tunnel and operatively connected to the motor. The left pod is disposed at a left of the central pod and is laterally spaced from the central pod. The left pod has a left hull that is narrower than the central hull. The right pod is disposed at a right of the central pod and is laterally spaced from the central pod. The right pod has a right hull that is narrower than the central hull.

Provided is a hull of a boat including a central portion of a bottom of the hull, side portions of the bottom of the hull, lateral to the central portion of the bottom of the hull, the central portion of the bottom of the hull being substantially lowered in a substantially discontinuous way with respect to the side portions of the bottom of the hull, central side walls separating the central portion of the bottom of the hull from the side portions of the bottom of the hull. The hull also having external side walls laterally external to the side portions of the bottom of the hull.