WO2012069809A1

WO2012069809A1 - A man overboard marking device

Info

Publication number: WO2012069809A1
Application number: PCT/GB2011/052250
Authority: WO
Inventors: Peter Brooke Evans
Original assignee: Peter Brooke Evans
Priority date: 2010-11-23
Filing date: 2011-11-17
Publication date: 2012-05-31
Also published as: GB201310437D0; GB2485788A; GB201019854D0; GB2499352B; GB2499352A; GB201108287D0

Abstract

A man overboard safety device (1) comprises a dispenser unit (3) for mounting on a vessel (7). A plurality of markers (9) are stored in chambers provided inside the dispenser unit (3) and are connected together by a line (11). The foremost marker (9) is connected to a primary drogue (13) stored in a dispensing tube in the dispenser unit (3). Means are provided to activate the device (1) to release the primary drogue (13) from the dispensing tube into the water. The primary drogue (13) applies a tensile force to the line (11) of markers (9), pulling the markers (9) sequentially from their storage chambers, through the dispensing tube and into the water. Once dispensed, the plurality of markers (9) form a string of markers in the water extending from the man overboard for a significant distance along the geographical track between the man overboard and the vessel (7) to indicate the position of the man overboard relative to the vessel (7).

Description

A MAN OVERBOARD MARKING DEVICE

The present invention relates to a man overboard safety device and particularly but not exclusively relates to a man overboard safety device for use on a vessel such as a yacht or motorboat for example.

The term 'man overboard' is used generically to refer to any person, animal or object that is accidentally separated from a moving vessel or from a fixed object in moving water such as an oil rig for example.

It is a well known risk of being on a vessel that one or more of the occupants could fall overboard. Once overboard it can be very difficult for the man overboard to remain in view of the vessel as once in the water only a small part of the man overboard projects above the water line and is typically obscured by the peaks and troughs of any waves. Even a slow moving vessel will relatively quickly open up a large distance between the vessel and the man overboard.

The current procedure for dealing with a man overboard typically involves inter alia, throwing a buoyancy aid to the man overboard and nominating a member of the crew of the vessel to maintain line of sight with the man overboard whilst the vessel turns around. This procedure is unreliable not least because it is difficult in practice to retain a line of sight, and indeed this may be impossible if there is only one person remaining on the vessel as that person will simultaneously also have to maintain control of the vessel.

This might be a particular issue therefore on a vessel with a small crew such as a yacht or motorboat. It is equally, however, a problem on larger boats such as military vessels, commercial vessels such as container ships and ferries, and leisure vessels such as cruise ships.

According to a first aspect of the invention there is provided a man overboard safety device comprising a dispenser unit comprising a housing, a plurality of markers releasably stored in the housing, and a dispensing assembly operative to effect the sequential release of the markers from the dispenser unit such that, when released in use into water where there is relative movement between the water and the dispenser unit, the markers form a spaced apart line of markers floating on the water.

The line of markers is intended in use to extend from the near vicinity of the man overboard for a significant distance along the geographical track between the man overboard and the vessel or fixed object from which the markers are dispensed to provide a visual indication of the position of, and direction to, the man overboard. The relative movement, that is, relative longitudinal movement, between the water and the dispenser unit might be caused by a tidal or non-tidal current for example, or by movement of the vessel making way in moving or non moving water.

Preferably the markers are stored in a stack or stacks in the dispenser unit.

The markers may be arranged to be pulled from the dispenser unit, when the dispensing assembly is activated.

The markers may be arranged to be dispensed from the dispenser unit by gravity, when the dispensing assembly is activated. The markers may be arranged to be released from the dispenser unit by an electromechanical release mechanism when the dispensing assembly is activated.

The electro-mechanical release mechanism may comprise at least one of a solenoid, a pneumatic actuator, and a hydraulic actuator to release the markers.

The dispensing assembly preferably comprises a dispensing aperture and a closure operative to open the aperture. The closure may seal the aperture. The closure may be movable from a closed to an open position, or may be releasable from the dispensing assembly.

The dispensing aperture may be provided in a lower part of the dispenser unit, or at one end of the dispenser unit.

The dispensing assembly may comprise a manually operated activation mechanism such as a pull cord operative to move the closure to open the dispensing aperture. The dispensing assembly may alternatively comprise an electro-mechanical activation mechanism operated via a user controlled switch, the electro-mechanical activation mechanism moving the closure to open the dispensing aperture. The electro-mechanical activation mechanism may comprise at least one of a solenoid, a pneumatic actuator, and a hydraulic actuator to move the closure.

The markers may be interconnected by a line. The markers may be equispaced along the line but alternatively could be at varying spacings. The markers may be closer together towards one or both ends of the line.

At least one marker could comprise at least one of a buoy, a flag, and a light.

Preferably each marker comprises a float which is substantially circular in transverse cross section.

Each float may be substantially spherical.

Preferably the markers are stored in the dispenser unit in at least one chamber. A plurality of chambers may be provided.

The dispenser unit may, in one example, be cylindrical. In this example, the chambers may be equispaced about the longitudinal axis of the dispenser unit. In another example, the dispenser unit may be cuboidal.

Preferably the or each chamber is defined by a plurality of dividing walls within the dispenser unit, the plane of each wall being substantially parallel with the longitudinal axis of the dispenser unit. Preferably the dispensing assembly comprises a dispensing tube extending up from a lower part of the dispenser unit into the dispenser unit, a lower end of the dispensing tube comprising a dispensing aperture, markers being dispensed by moving down the dispensing tube and through the dispensing aperture. Where the dispenser unit is cylindrical, the dispensing tube may be substantially coaxial with the longitudinal axis of the dispenser unit, the at least one chamber being spaced radially outwardly of the dispensing tube. Where the dispenser unit is cuboidal, the dispensing tube may be substantially coaxial with the longitudinal axis of the dispenser unit, or alternatively the dispensing tube may be parallel to but not coaxial with the longitudinal axis of the dispenser unit.

Preferably the device further comprises at least one drogue, the drogue comprising a body adapted to be at least partially submerged when in the water so as to resist movement through the water, the drogue being connected by a line to at least one marker to provide an anchoring force on the marker.

A shock cord may be incorporated in the connection between the drogue and the first marker to limit shock loading on the line.

Preferably the drogue and markers are arranged in the dispenser unit such that the drogue is a primary drogue dispensed first, before the markers. A terminal sea anchor may be arranged in the dispenser unit such that the sea anchor is dispensed last, after all of the markers.

Intermediate drogues may be arranged in the dispenser unit so as to be dispensed between adjacent markers.

Preferably a, or at least one, drogue is arranged, when released from the dispenser unit, to pull the subsequent markers from the at least one chamber, through the dispensing tube, and out of the dispenser unit via the dispensing aperture, by means of a tension force imparted on a line connecting the markers.

Most preferably the primary drogue is arranged to be stored in the dispenser unit within the dispensing tube.

Preferably a spool is provided at the upper end of the dispensing tube, within the dispenser unit, the line to which the markers are attached being wrapped around the spool when the markers are stored in the dispenser unit, the markers being retained in the at least one chamber.

A guide cone may be provided above the spool operative to guide the line from the spool into the dispensing tube as the markers are moved from the at least one chamber and out of the dispenser unit.

The guide cone may be rotatably mounted on the dispensing tube. At least one marker may comprise an inflatable portion operative to inflate automatically once released from the dispenser unit.

According to a second aspect of the invention there is provided a plurality of markers for use with a man overboard safety device according to the first aspect of the invention.

Other aspects of the present invention may include any combination of the features, components or limitations referred to herein. The present invention may be carried into practice in various ways, but an embodiment will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a schematic view of a man overboard safety device in accordance with the invention, with a line of markers of the device in a dispensed condition;

Figure 2 is a perspective view of a man overboard safety device in accordance with the invention, mounted on a motor boat, with the line of markers in a stored condition;

Figure 3 is a perspective view of the man overboard safety device of Figures 1 and 2 with part of the line of markers in a stored condition, the walls of the dispenser unit of the device being shown in phantom, and the connecting line having been omitted, for clarity; Figure 4 is a plan view corresponding to Figure 3 ;

Figure 5 is an enlarged sectional side view of an upper part of the device of Figures 3 and 4;

Figure 6 is a side view of a drogue comprising part of the man overboard safety device of Figures 1 to 5, with the drogue in a deployed condition;

Figure 7 is a perspective view of a further example of a man overboard safety device in accordance with the invention, with the line of markers in a stored condition, the walls of the dispenser unit of the device being shown in phantom.

Figure 8 is a sectional side view of another drogue comprising part of the man overboard safety device of Figures 1 to 7, with the drogue in a storage condition;

Figure 9 is a sectional side view of the drogue of Figure 8 in a deployed condition; and

Figure 10 is a sectional side view of a further drogue comprising part of the man overboard safety device of Figures 1 to 7, with the drogue in a storage condition.

Referring initially to Figures 1 to 4, a man overboard safety device 1 comprises dispenser unit 3 the exterior of which is provided with a mount in the form o bracket 5 arranged to mount the dispenser unit 3 to a suitable part of the exterior of vessel such as boat 7. The dispenser unit 3 is cylindrical in this example. The man overboard safety device 1 further comprises a plurality of buoyant markers 9 which in this example are interconnected via line 1 1. The dispenser unit 3 is arranged such that the markers 9 and line 1 1 are stored in the dispenser unit 3 and can be dispensed therefrom in a man overboard situation. Once fully dispensed, ie free of the dispenser unit 3, the markers 9 are spaced apart along the line 1 1 extending from near the vicinity of the man overboard for a significant distance along the geographical track between the man overboard and the boat 7 to provide a visible guide to the position of the man overboard, relative to the boat 7.

In this example a primary drogue 13 is provided at one end of the line 1 1 and is arranged to be submerged in the water to act as an anchor for the markers 9 and line 1 1.

Between the primary drogue 13 and the first marker 9A, is a float 15 designed to generate a buoyant force that acts against the primary drogue 13 and its weight 41 to prevent the primary drogue 13 from adversely affecting the buoyancy of the markers 9. In addition a length of shock cord (not shown) may be incorporated into the line 1 1 connecting the primary drogue 13 to the first marker 9A to reduce the shock loading on the components. At the other end of the line 1 1 is a terminal sea anchor 18. In this example the sea anchor 18 comprises a component of similar size and shape to float 21 but with a perforated casing and slight negative buoyancy such that it sinks below surface of water. The terminal sea anchor 18 functions to anchor the other end of line 1 1 once the line 1 1 is fully dispensed into the water. The drogue 13 and sea anchor 18 thus minimise the effects of the wind dragging the markers 9 away from their position relative to the man overboard.

The drogue 13 and sea anchor 18 serve to anchor the line of markers 9 within the body of water to drift with the current to match the drift of the man overboard.

Each marker 9, in this example, comprises a marker string 19 connected to the main line 1 1 , and a float 21. Each float 21 comprises a highly visible coloured buoy in this example. The colours of adjacent buoys may vary along the line 1 1 , and may be in a repeating pattern to indicate the direction of travel. Weights 22 may be provided on each marker string 19 below the float 21 to weigh the main line 1 1 below the water line to minimise the effect of the wind blowing the floats 21 away from the desired position.

Referring in particular to Figures 3 to 5, the dispenser unit 3 comprises a hollow cylindrical housing having a removable lid 4 closing the upper end. A dispensing tube 23, coaxial with the longitudinal axis of the housing, comprises part of a dispensing assembly and extends from a lower part of, and in this example, the base of, the housing to a position about three quarters of the way up. The lower end of the dispensing tube 23 projects through the base of the housing to the extent that it defines a dispensing aperture 25.

The dispensing aperture 25 is provided with a closure (not shown) to close the dispensing aperture 25. The closure may comprise a pivoting, sliding or removable cap or disc for example. The closure may seal the aperture 25.

The dispensing assembly further comprises an actuator operative to move the closure to open the dispensing aperture 25. The actuator may comprise a manually operated handle or rip cord, or may comprise an electro-mechanical actuator such as a button operated solenoid, or pneumatically or hydraulically powered ram. If an electro- mechanical actuator is used, it may be activated remotely via a suitable 'man overboard' button or switch either near the dispenser unit 3 , or elsewhere on the boat, for example in the cabin, or cockpit.

The annular space around the central dispensing tube 23 is divided into a plurality of marker chambers 27 by radially outwardly extending dividing walls 29.

The upper end of the dispensing tube 23 projects above the top of each dividing wall 29, and a guide cone 31 is mounted thereon. The guide cone 31 is mounted above a spool 33. The guide cone 31 has a flared upper portion 35. Above the flared portion 35 is a bevelled end piece 37 that fits onto the upper end of the dispensing tube 23 to provide a smooth, curved guide surface for the line 1 1 to pass over in use.

In this example the guide cone 31 is rotatable around the dispensing tube 23 but it may alternatively be fixed.

The markers 9, sea anchor 18, and any intermediate drogues, are stored in stacked formation in the various chambers 27 around the central dispensing tube 23. The primary drogue 13 together with its weight 41 and drogue float 15 are stored in the dispensing tube 23 itself. The line 1 1 between each marker 9, and most of the line 1 1 between the first marker 9 A and primary drogue 13 is wound around the spool 33 such that only the marker strings 19 extend into the chambers 27. This ensures that the line 1 1 does not become tangled during dispensing from the dispenser unit 3. The line 1 1 is prevented from inadvertently unwinding prior to activation by releasably securing the section of line 1 1 between the spool 33 and the top of the dispensing tube 23 in a restraining clip (not shown).

In use, in a man overboard situation, a crew member of the boat 7 activates the dispensing assembly either by pressing the appropriate button or switch, or by manual activation as appropriate. This releases the closure, opens the dispensing aperture 25, and allows the primary drogue 13 to drop from the dispensing tube 23 under the influence of gravity. An extension or chute 23A may be provided beneath the dispensing tube 23 to guide the primary drogue 13 away from the boat 7 and into the water. The primary drogue 13, when in the water, generates drag sufficient to release line 1 1 from the restraining clip and to pull the line 1 1 and the first marker 9A through the dispensing tube 23. As the line 1 1 is pulled, it unwinds from the spool 33 and passes over the guide cone 31 and bevelled end piece 37. When viewed from above during dispensing, the line 1 1 rotates around the dispensing tube 23 similarly to a fishing line unravelling from a fixed spool fishing reel.

When a sufficient length of line 1 1 has been pulled through the dispensing tube 23 the continued tension on the line 1 1 pulls a subsequent marker 9 upwardly from one of the storage chambers 27, over the guide cone 31 and bevelled end piece 37 and into the upper end of the dispensing tube 23. The marker 9 drops down the dispensing tube 23, through the dispensing aperture 25, and into the water where the buoyancy of the marker 9 ensures that the marker 9 is visible from the boat 7.

This process repeats such that markers 9 are sequentially dispensed from the dispenser unit 3. It is envisaged that the markers 9 may be stored in the dispenser unit 3 such that they are dispensed from adjacent chambers 27 sequentially, or all of the markers 9 from one chamber 27 could be dispensed before the markers 9 in the next chamber 27 are dispensed. Any appropriate method or sequence could be used as preferred. Once dispensed, the relative movement between the boat 7 and the water ensures that the markers 9 are spaced apart in the water extending from the near vicinity of the man overboard for a significant distance along the geographical track between the man overboard and the boat 7. The spacing of the markers 9 is determined by the length of line 1 1 between adjacent markers 9 - more line between each marker 9 increases the spacing achieved. Any suitable length of line 1 1 can be used and it is envisaged that the total length of the line 1 1 be at least 150 metres long in this example.

Once the closure is moved to open the dispensing aperture 25, the dispensing of the markers 9 from the dispenser unit 3 is automatic, requiring no user intervention, provided that there is continuing relative longitudinal movement between the water and the dispenser unit 3.

It will be appreciated that any suitable bracket 5 or other means of attachment may be used, as required to mount the dispenser unit 3 on any desired part of a boat. In this example, the boat 7 is a leisure or recreational motor boat but the dispenser unit 3 may equally be used on sailing yachts, larger vessels, or military, commercial or passenger vessels for example. The means of attachment may simply comprise an aperture or pair of apertures on the external casing of the dispenser unit 3 to enable a jubilee clip or the like to be used.

Referring additionally to Figure 6, the primary drogue 13 is arranged to be expandable from a storage condition to an operational condition. The drogue 13 comprises a collapsible, fabric, frustroconical kite 38 the wider end of which is attached to a plurality of suspension cords 39 that extend from the kite 38 to an attachment block 40. The block 40 is connected to main line 1 1 via a drogue weight 41. The connection between drogue 13 and line 1 1 may include a length of shock cord (not shown). When in the storage condition, the folded kite 38 and suspension cords 39 are contained within the dispensing tube 23 with the drogue weight 41 and the drogue float 15. The kite 38 and cords 39 are retained in the dispensing tube 23 by the movable closure. In use, on activation of the dispensing assembly, the weight of the kite 38 and drogue weight 41 is sufficient that the kite 38, drogue weight 41 and drogue float 15 slide out of the dispensing tube 23 through aperture 25. When in the water, the kite 38 fully expands at which stage the frustroconical shape of the kite 38 causes drag in the water which resists deviation of the drogue 13 from the position in which it was first dispensed.

Referring additionally to Figure 7, a further example of a man overboard device 101 comprises a dispenser unit 3 which is cuboidal in this example. The device 101 has similar features to the device 1 described above, like features having been given like references.

In this example, the dispensing tube 23 is again mounted centrally in the dispenser unit 3 although alternatively the tube may be mounted off centre. The chambers 27 are arranged in pairs extending away from each side of the dispensing tube 23.

The cuboidal dispenser unit 3 is therefore expandable in terms of the number of chambers 27 provided. Thus the outermost pair(s) of chambers 27 may be omitted, or additional pairs of chambers 27 added as required.

The method of dispensing is as described above with reference to device 1 except that the arrangement of markers 9 is such that the markers 9 in the outermost chambers 27 are dispensed before the markers 9 from the inwardly adjacent chambers 27. Dispenser unit 3 is also provided with a rip cord conduit 105 that extends vertically adjacent to the dispensing tube 23 so that a rip cord handle (not shown) can be provided at the top of the dispenser unit 3. The rip cord handle may be used to activate the dispensing assembly by releasing the closure when the rip cord handle is pulled. The rip cord conduit 105 may equally be provided on the cylindrical dispenser unit 3 of device 1.

Each marker 9 may be of any desired construction to enable a part of the marker 9 to be visible from the dispensing, or any, boat or rescue craft. To this end, it is envisaged that each marker 9 be arranged to project from the surface of the water. The projecting part of the marker 9 may comprise the upper part of a spherical or cylindrical buoy, or may comprise a shaft to which is mounted a flashing light, flag or other highly visible positional indicator.

A counterweight may be provided at the bottom of each marker 9 to ensure the visible part of the marker 9 projects up from the surface of the water and to enhance buoyant and positional stability.

Each marker 9 may be provided with indicia indicative of the relative position of that marker 9 relative to other markers 9. The indicia may comprise a coloured portion of the marker, or a number or letter for example. This could indicate the direction of travel, or distance to the first marker 9A for example.

Each marker 9 may be telescopic or incorporate a suspendable lower weighted section that sinks below the upper section to add resistance when in the water. The lower weighted section could be attached via a line. This would enable each marker 9 to be stored in a compact condition in the dispenser unit 3, extending to an extended condition when in the water to improve buoyant and positional stability.

Each marker 9 may comprise a housing portion in which a deflated bladder is located when the marker is in the stored condition. When in the water, the bladder is arranged to inflate to provide buoyancy to the marker 9.

The line 1 1 may be provided at any point, or at multiple points, with a weakened link adapted to break if the line 1 1 snags on another object, such as the propeller of a boat for example. The weakened link is arranged to have a tensile strength below that of the line 1 1 itself.

It is envisaged that the line 1 1 may be omitted altogether if the dispensing assembly is arranged with an electro-mechanical release mechanism to automatically dispense the markers 9 in the required sequence and spacing. For example the electro-mechanical release mechanism may be controlled by an electronic controller to actuate the electro-mechanical release mechanism at predetermined time or distance intervals, a marker 9 being released at each time interval. Thus in this example, the release and spacing of the markers 9 is controlled by the electronic controller rather than an interlinking line 1 1. The markers may be stored in the dispenser unit 3 in a marker stack which may be a helical channel to maximise the number of markers that can be stored in a given size of dispenser unit 3. The dispenser unit 3 may be in the form of an elongate tube or channel, with the dispensing aperture 25 at one end. The markers may be indexed toward the dispensing aperture 25 by a movable track or conveyor within the dispenser unit 3. The helical track may extend around the central dispensing tube 23, or the dispensing aperture may be located at the bottom of the helical track itself, the dispensing tube 23 being omitted. The markers may be stored in the dispenser unit 3 in racks or shelves within the dispenser unit 3, each marker being temporarily held in the desired location by a suitably sized slot or finger for example.

The line 1 1 instead of being wrapped around a spool for storage, could instead be wrapped around a shaft of each individual marker.

It is envisaged that the dispenser unit 3 be made of any suitable material which may include a plastic or GRP based material. Detent means may be provided to retain the markers 9 in chambers 27 in the event the dispenser unit 3 is inverted. The retaining means may comprise a compressible throat or leaf spring retainers or the like at the top of each chamber 27 to engage the upper most marker 9 in each chamber 27. A Dan-Buoy mounting tube may optionally be incorporated in the dispenser unit 3. Optionally a Dan-Buoy (not shown) may be mounted in the mounting tube (not shown) extending through the dispenser unit 3 (in place of one of the outermost chambers 27) or affixed to the outer casing of the dispenser unit 3. The Dan-Buoy may be attached to the rip cord so that release of the Dan-Buoy activates the dispensing assembly.

With reference to Figures 8 and 9, optionally an intermediate drogue 17B may be incorporated in the line of markers 9 and is arranged to be expandable from a storage condition to a dispensed, operational condition. The intermediate drogue 17B is of similar structure to the primary drogue 13 and like features have been given like references. When in the storage condition, the folded kite 38 and suspension cords 39 are contained within a spherical casing 43 of similar size and shape to the floats 21 of markers 9. Part of the casing 43 comprises an aperture 48 through which the kite 38 and cords 39 pass when moving to the operational condition. Again the kite suspension cords 39 extend from the kite 38 to an attachment block 40. The block 40 is connected to main line 1 1 via a drogue weight 41 , the main line l lbeing affixed to the rear of the casing 43 via an internal connector 45B. The attachment block 40 is also connected to the upstream part of line 1 1 via connections at a securing disc 49. The line 1 1 is also secured to the casing 43 via a releasable nipple 47. The nipple 47 is held in place inside the casing 43 via a securing disc 49 at the aperture 48. This serves to wrap part of the line 1 1 around the casing 43 whilst the intermediate drogue 17B is stored in the dispenser unit 3 to minimise the possibility of the line 1 1 becoming tangled.

The securing disc 49 is itself held in place inside the casing 43 by a water deactivated retainer which in this example comprises a dissolvable (eg paper) plug 51 that engages the securing disc 49 and the margin of the aperture 48. In use, the casing 43 drops into the water through dispensing tube 23 as described above. When in the water, the plug 51 dissolves, releasing the securing disc 49 from inside the casing 43. This in turn releases the nipple 47 and thus allows the downstream part of the line 1 1 to unwrap from around the casing 43 and extend from the rear of the casing 43 via external connector 45A. This applies tension between the released downstream part of the line 1 1 and the upstream part of the line 1 1 , which is attached to casing 43 via internal connector 45B and to block 40 of the kite 38. This tension pulls the suspension cords 39 and the kite 38 from the inside of the casing 43 and the kite 38 expands as described above. Optionally, it might be desirable to have one group of markers on line 1 1 releasable from another group of markers on line 1 1. This would create two or more separate lines of markers 9 in the water. The intermediate drogue 17B can be either fixed within a single line of markers 9 as described above, or alternatively it can incorporate a releasable link 55 so that the line of markers 9 can split into two or more independent lines of markers 9. To this end, the kite 38 is connected to the upstream line 1 1 via a releasable link 55. To ensure the intermediate drogue 17B is discharged cleanly from the dispenser unit 3, it is stored in a spherical casing 43 as described above. The intermediate drogue 17B is packed, together with its weight 41 , into the hollow casing 43 and retained in place by the securing disc 49 which is itself retained by the soluble paper plug or annulus 51. The upstream connecting line 1 1 attaches to the securing disc 49 and thence to a releasable connector pin 63.

The releasable connector pin 63 is retained within a releasable link body 57, which is integral with the crown of the kite 38 of the drogue 17B, by two half round keys 65 which locate in respective blind keyways 67 within the releasable connector pin 63 and respective slots in the releasable link body 57.

The keys 65 are initially retained in position by a releasable link cap 59 which is tethered 61 to the inside of the casing 43 at the internal connector 45B, as are the cords 39 from the drogue 17B.

Following deployment of the spherical casing 43, the paper plug 51 dissolves allowing the securing disc 49 to be released. This frees the nipple 47 allowing the connecting point for the downstream connecting line 1 1 to move to the external connector 45A. The resulting tension forces pull the intermediate drogue 17B from the casing 43, following which the kite 38 is able to deploy. As the tether line 61 is pulled taught, the releasable link cap 59 is pulled from the releasable link body 57 allowing the half round keys 65 to fall clear, thereby releasing the releasable connector pin 63. Optionally a terminal drogue 17A may be used in place of sea anchor 18. Referring additionally to Figure 10, a terminal drogue 17A is stored in a similar casing 43 to the intermediate drogue 17B, as described above with reference to Figures 8 and 9, like references being used for like features. The terminal drogue 17A operates by means of the drogue 17A being pulled from the casing 43 immediately on discharge from the dispenser unit 3. Consequently the soluble paper plug closure arrangement of Figure 8 is not appropriate, and is replaced with a removable flexible cap 71.

The basic arrangement of the casing 43 is similar to that of Figures 8 and 9 but the orientation is reversed such that the downstream end of line 1 1 is tethered to the base of the chamber 27 within the dispenser unit 3. The length of downstream line 1 1 is just sufficient for the casing 43 to fall clear of the dispensing aperture 25 when released from the dispenser unit 3. The downstream line 1 1 then becomes taut pulling the flexible cap 71 from the aperture 48 and thence the releasable link 55 together with the drogue kite 38, attachment block 40 and weight 41. When all these components are removed from the casing 43, the line 61 between the flexible cap 71 and the internal connector 45B becomes taut thereby pulling releasable link cap 59 from the releasable link body 57 thereby severing the connection between the drogue 17A and the dispenser unit 3. The relative lengths of the suspension cords 39 and the line 61 connecting the releasable link cap 59 are designed so as to ensure the releasable link cap 59 is pulled from the releasable link body 57.

Claims

1. A man overboard safety device comprising a dispenser unit comprising a housing, a plurality of markers releasably stored in the housing, and a dispensing assembly operative to effect the sequential release of the markers from the dispenser unit such that, when released in use into water where there is relative movement between the water and the dispenser unit, the markers form a spaced apart line of markers floating on the water.

2. The man overboard safety device of claim 1 wherein the markers are stored in a stack in the dispenser unit.

3. The man overboard safety device of claim 1 or claim 2 wherein the markers are arranged to be pulled from the dispenser unit, when the dispensing assembly is activated.

4. The man overboard safety device of any one of the preceding claims wherein the markers are arranged to be dispensed from the dispenser unit by gravity, when the dispensing assembly is activated.

5. The man overboard safety device of any one of the preceding claims wherein the markers are arranged to be released by an electro-mechanical release mechanism, when the dispensing assembly is activated.

6. The man overboard safety device of claim 5 wherein the electro-mechanical release mechanism comprises at least one of a solenoid, a pneumatic actuator, and a hydraulic actuator to release the markers.

7. The man overboard safety device of any one of the preceding claims wherein the dispensing assembly comprises a dispensing aperture and a movable closure operative to open the aperture.

8. The man overboard safety device of claim 7 wherein the dispensing aperture is provided in a lower part of the dispenser unit.

9. The man overboard safety device of claim 7 or claim 8 wherein the dispensing assembly comprises a manually operated mechanism such as a pull cord operative to move the closure to open the dispensing aperture.

10. The man overboard safety device of claim 7 or claim 8 wherein the dispensing assembly comprises an electro-mechanical activation mechanism operated via a user controlled switch, the electro-mechanical activation mechanism moving the closure to open the dispensing aperture.

1 1. The man overboard safety device of claim 10 wherein the electro-mechanical activation mechanism comprises at least one of a solenoid, a pneumatic actuator, and a hydraulic actuator to move the closure.

12. The man overboard safety device of any one of the preceding claims wherein the markers are interconnected by a line.

13. The man overboard safety device of any one of the preceding claims wherein each marker comprises a projection that projects above the surface of the water in use.

14. The man overboard safety device of any one of the preceding claims wherein each marker is substantially circular in transverse cross section.

15. The man overboard safety device of claim 14 wherein each marker is substantially spherical.

16. The man overboard safety device of any one of the preceding claims wherein the markers are stored in the dispenser unit in at least one chamber.

17. The man overboard safety device of claim 16 wherein a plurality of chambers are provided.

18. The man overboard safety device of any one of claims 16 or 17 wherein the or each chamber is defined by a plurality of dividing walls within the dispenser unit, the plane of each wall being substantially parallel with the longitudinal axis of the dispenser unit.

19. The man overboard safety device of any one of the preceding claims wherein the dispensing assembly comprises a dispensing tube extending up from a lower part of the dispenser unit into the dispenser unit, a lower end of the dispensing tube comprising a dispensing aperture, markers being dispensed by moving down the dispensing tube and through the dispensing aperture.

20. The man overboard safety device of any one of the preceding claims wherein the device further comprises at least one drogue, the drogue comprising a body adapted to be at least partially submerged when in the water so as to resist movement through the water, the drogue being connected to at least one marker to provide an anchoring force on the marker.

21. The man overboard safety device of claim 20 wherein the drogue and markers are arranged in the dispenser unit such that the drogue is a primary drogue dispensed first, before the markers.

22. The man overboard safety device of claim 20 wherein the drogue comprises an intermediate drogue arranged in the dispenser unit so as to be dispensed between adjacent markers.

23. The man overboard safety device of any one of claims 20 to 22 wherein a, or at least one, drogue is arranged, when released from the dispenser unit, to pull the subsequent markers from the at least one chamber, through the dispensing tube, and out of the dispenser unit via the dispensing aperture.

24. The man overboard safety device of claim 21 wherein the primary drogue is arranged to be stored in the dispenser unit within the dispensing tube.

25. The man overboard safety device of any one of claims 21 to 24 wherein a spool is provided at the upper end of the dispensing tube, within the dispenser unit, the line to which the markers are attached being wrapped around the spool when the markers are stored in the dispenser unit, the markers being retained in the at least one chamber.

26. The man overboard safety device of claim 25 wherein a guide cone is provided above the spool operative to guide the line from the spool into the dispensing tube as the markers are moved from the at least one chamber and out of the dispenser unit.

27. The man overboard safety device of any one of the preceding claims wherein at least one marker comprises an inflatable portion operative to inflate automatically once released from the dispenser unit.

28. The man overboard safety device of any one of the preceding claims wherein the markers are inherently buoyant.

29. A plurality of markers for use with a man overboard safety device according to any one of claims 1 to 28.