Unmanned marine sailing vessel

1. An unmanned surface vessel comprising:

a hull;

an underwater appendage in the form of a keel which is at least in part hollow thereby defining a cavity, the keel being attached to the hull;

a winch located at least partly within the cavity, the winch arranged to cooperate with a cable or rope to be deployed and retrieved from the vessel via operation of the winch;

the keel including at least one aperture through which the cable or rope passes, said aperture being adapted to permit the ingress of water from outside the hull into at least the cavity of the keel improving the righting moment of the unmanned surface vessel.

2. An unmanned surface vessel as claimed in claim 1 wherein the winch is substantially aligned with a vertical axis of the keel and a maj ority of the winch is located within the cavity improving the righting moment of the vessel, the winch having an axis of rotation oriented substantially perpendicular to the keel's vertical axis.

3. An unmanned surface vessel as claimed in claim 1 also comprising a housing fixed internally of the hull and designed to contain the winch, the housing arranged to contain water substantially within the cavity of the keel.

4. An unmanned surface vessel as claimed in claim 3 wherein the housing is arranged to retractably receive a cassette including the winch.

5. An unmanned surface vessel as claimed in claim 1 wherein the winch is designed to allow and contain spooling of the cable or rope, sufficiently constrained as to reduce the likelihood of overriding of the cable or rope within the winch.

6. An unmanned surface vessel as claimed in claim 5 wherein the winch includes a central hub and an opposing pair of flanges mounted either side of the hub, the flanges being separated a distance equal to or slightly greater than the diameter of the cable or rope.

7. An unmanned surface vessel as claimed in claim 1 wherein the cable or rope includes a remote device mounted at its distal end.

8. An unmanned surface vessel as claimed in claim 7 wherein the aperture is sized to permit passage of the remote device on retrieval of the cable or rope via the winch, the remote device thus being stowed within the cavity of the keel.

9. An unmanned surface vessel as claimed in claim 7 wherein the remote device includes a sensor, camera, or sampler.

10. An unmanned surface vessel as claimed in claim 1 further comprising a rudder located forward of the keel thereby reducing likelihood of the cable or rope fouling the rudder on deployment of the cable or rope.

11. An unmanned surface vessel as claimed in claim 1 wherein the unmanned surface vessel is a sailing vessel.

12. An unmanned surface vessel comprising:

a hull;

an underwater appendage in the form of a keel which is at least in part hollow thereby defining a cavity, the keel being attached to the hull and adapted to permit flooding of water from outside the hull into at least the cavity of the keel;

a housing fitted internally of the hull and surrounding the cavity, the housing adapted to contain the flooded water substantially within the cavity;

a local device located at least partly within the cavity.

13. An unmanned surface vessel as claimed in claim 12 wherein the keel includes an aperture which permits the ingress of water into the cavity for its flooding.

14. An unmanned surface vessel as claimed in claim 12 wherein the local device is in the form of a cassette which is retractably received in the housing.

15. An unmanned surface vessel as claimed in 12 wherein the local device includes sonar, camera, sensor, batteries or any one or more combinations of these active or passive local devices.