System for transferring resources in a body of water and installation method for installing said system

Abstract

A system for transferring resources in a body of water has a surface station (4) configured to generate electrical energy and transceive data; an underwater station (5) that can be connected to an unmanned underwater vehicle (3); a depth buoy (6); and an umbilical (7), which connects electrically and for data exchange the surface station (4) to the underwater station (5) via the depth buoy (6); the system (1) being configured to selectively assume in the body of water (2) a launch and recovery configuration, in which the surface station (4), the depth buoy (6) and the underwater station (5) are joined mechanically; and an operative configuration, in which the underwater station (5) is laid on a bed (8) of the body of water (2) and the depth buoy (6) is placed at a specified depth in the body of water (2).

Description

[0001] "SYSTEM FOR TRANSFERRING RESOURCES IN A BODY OF WATER AND INSTALLATION METHOD FOR INSTALLING SAID SYSTEM"

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This Patent Application claims priority from Italian Patent Application No . 102024000003682 fi led on February 21 , 2024 , the entire disclosure of which is incorporated herein by reference .

[0004] TECHNICAL FIELD

[0005] The present invention relates to a system for exchanging resources , in particular energy and data, in a body of water, with an unmanned underwater vehicle . In further detail , the present invention relates to a system for providing resources from the surface of the body of water to an unmanned underwater vehicle (UV) temporarily residing in an underwater installation field .

[0006] In addition, the present invention relates to a method for installing said system . In particular, the present invention finds advantageous application in deep waters . STATE OF THE ART

[0007] In the industry dealing with the construction of underwater infrastructure , the underwater plant engineering component has become increasingly important . In this scenario , the use of unmanned, tethered underwater vehicles (ROVs , "Remote Operated Vehicles" ) is widespread and is a tool for operating said infrastructure in contexts that are dangerous for humans .

[0008] These underwater vehicles can perform a wide variety of operations commonly referred to as inspection, monitoring, maintenance and repair of underwater infrastructure .

[0009] Typically, tethered underwater vehicles are equipped with a lightweight umbilical cable ("tether" ) , which serves to power and control the underwater vehicle and is wound and unwound such as to allow the underwater vehicle to navigate with greater freedom . This function of winding and unwinding the lightweight umbilical cable is performed by a remotely actuated and operated reel contained within a Tether Management System ( TMS ) located in the body of water at a depth compatible with that of the underwater vehicle .

[0010] Alternatively, underwater vehicles can also be tether- and TMS- free (AUV, "Autonomous Underwater Vehicle" ) , and equipped with built-in batteries and a control unit in which arti ficial intell igence algorithms are implemented to enable autonomous missions .

[0011] In recent decades , the development of underwater electronic components and control systems , and the growing demand from underwater field operators for underwater infrastructure management and maintenance services , have required the advent of resident underwater vehicles .

[0012] Generally, resident underwater vehicles operate close to the bed of the body of water and can be connected to at least one base underwater station, which is located on the bed of the body o f water and provides operational support to underwater vehicles , including power supply and data exchange . In this way, these resident underwater vehicles eliminate the need for surface support vessels (MSV, "Marine Support Vessel" ) and thus reduce costs , operational risks , and environmental impact , but require electrical energy and data from infrastructure located in the underwater field, thereby limiting the operational range of the underwater vehicles .

[0013] To overcome this inconvenience , temporarily resident systems providing energy autonomy to the underwater vehicle and which are relocatable have been designed to simpli fy many tasks and installation works that can be carried out without the need for surface crane vessels or other means of support .

[0014] Document WO 2019 / 123080 describes an example of a resident system for trans ferring power and data in a body of water to underwater vehicles when a direct underwater power and communication link to the underwater infrastructure is not available . Said system comprises a floating surface station configured to generate electrical energy and transceive data ; a base underwater station which can be connected to an unmanned underwater vehicle ; and an umbilical , which comprises a power transmission line and a data transmission line and electrically connects the surface station to the underwater station .

[0015] However, the installation costs of said resident system are still too high, due to the installation requirements requiring support vessels equipped with deep-water cranes and additional underwater vehicles necessary to assist underwater operations and to establish the connections of such a resident system . OBJECT OF THE INVENTION

[0016] One obj ect of the present invention is to provide a system for trans ferring resources in a body of water to an unmanned underwater vehicle , which mitigates the drawbacks of the prior art .

[0017] In particular, one obj ect of the present invention is to simpli fy the installation by means of a system that can be installed with a single li ft and is sel f-installing, easily relocatable and maintains the advantages of the resident system described in the prior art , so as to be able to operate in large underwater fields .

[0018] In accordance with the present invention, a system for trans ferring resources in a body of water to an unmanned underwater vehicle is provided, the system comprising :

[0019] - a floating surface station, which is configured to generate electrical energy and transceive data ;

[0020] - an underwater station connectable to at least one unmanned underwater vehicle ;

[0021] - a depth buoy; and

[0022] - an umbilical , which comprises at least one power transmission line and at least one data transmission line and connects electrically and for data exchange the surface station to the underwater station via the depth buoy; the system being configured to selectively assume in the body of water :

[0023] - a launch and recovery configuration, in which the surface station, the depth buoy and the underwater station are mechanically j oined to form a single assembled body; and

[0024] - an operative configuration, in which the underwater station is laid on a bed of the body of water and the depth buoy is placed at a speci fied depth in the body of water at a distance from the underwater station and from the surface station .

[0025] The present invention enables the system to be installed in the body of water in a simple , fast and cost-ef fective way, without the need to carry out complex underwater operations and to use additional underwater vehicles , dedicated components and speciali zed technical personnel .

[0026] In other words , it is possible to set up a system that is substantially sel f-installing and temporarily resident in the field, to provide power to an unmanned underwater vehicle and the possibility of controlling said underwater vehicle via surface communication to a control station operated by pilots and / or operators .

[0027] By way of example , in the case of large underwater fields , the system can be installed in the body of water at a given underwater infrastructure and then relocated quickly and easily to another underwater infrastructure .

[0028] In particular, the surface station comprises a f irst mechanical connector ; the depth buoy comprising a second mechanical connector configured to selectively couple to / uncouple from the first mechanical connector so as to mechanically connect / disconnect the surface station to / from the depth buoy .

[0029] This allows the depth buoy and underwater station to be uncoupled from the surface station during the system installation operations .

[0030] In other words , it is possible to keep the surface station on the surface while the depth buoy and the underwater station are lowered deep into the body o f water, deploying a first portion of the umbilical .

[0031] In particular, the underwater station comprises a third mechanical connector ; the depth buoy comprising a fourth mechanical connector configured to selectively couple to / uncouple from the third mechanical connector so as to mechanically connect / disconnect the underwater station to / from the depth buoy .

[0032] This allows the underwater station to be uncoupled from the depth buoy during the system installation operations .

[0033] In other words , it is possible to keep the depth buoy at a certain depth in the body of water while the underwater station is lowered into the body of water until it reaches the bed of the body of water, deploying a second portion of the umbilical .

[0034] In particular, the depth buoy comprises a locking mechanism configured to selectively bind / unbind the depth buoy to / from the umbilical .

[0035] This allows the depth buoy to be locked at a certain portion of the umbilical . In practice , during the system installation operations , it is possible to bind the depth buoy to the umbilical while uncoupling the underwater station from the depth buoy so as to lower the underwater station into the body of water while keeping the position of the depth buoy in the body of water fixed .

[0036] In addition, when submerged in the body of water , as the depth buoy has a positive hydrostatic attitude , the depth buoy receives an upward hydrostatic thrust while keeping the second section of the umbilical taut .

[0037] In particular, the underwater station comprises a winch configured to selectively unwind / wind the umbilical so as to adj ust a length of the first and / or the second section of the umbilical .

[0038] In this way, during the system installation operations , it is possible to lower the depth buoy and the underwater station without the need to use a deep-water crane and / or additional machinery on board a support vessel , but only by means of shallow-water cranes having low li fting power and limited reach .

[0039] Furthermore , during the system installation operations , the deployment of the umbilical us ing a winch placed on the underwater station allows the umbi lical to be kept taut , so as to prevent the umbilical from being entangled or damaged . In particular, the system compri ses a support vessel provided with a control station, which is in communication with the surface station, and a launch and recovery crane , which is configured to launch and recover the system in the launch and recovery configuration .

[0040] In this way, the installation of the system in the body of water can be supported and, once installed, the operation of the system can be controlled in the operative configuration .

[0041] A further obj ect of the present invention is to provide an installation method for installing a system for trans ferring resources in a body of water, which mitigates the drawbacks of the prior art .

[0042] In accordance with the present invention, an installation method for installing a system for trans ferring resources in a body of water is provided as described above , the installation method comprising the steps of : arranging the system in the launch and recovery configuration, in which the surface station, the depth buoy and the underwater station are mechanically j oined to form a single assembled body;

[0043] - launching into the body of water the system in the launch and recovery configuration;

[0044] - uncoupling the surface station from the depth buoy and the underwater station;

[0045] - deploying a first section of the umbilical so as to lower the depth buoy and the underwater station into the body of water ;

[0046] - uncoupling the underwater station from the depth buoy;

[0047] - binding the depth buoy to the umbilical at a distance from the surface station; and - deploying a second section of the umbilical so as to lower the underwater station onto the bed of the body of water .

[0048] The present method enables the system to be installed in the body of water in a simple , fast and cost-ef fective way, avoiding the use of additional underwater vehicles , dedicated components and speciali zed technical personnel . BRIEF DESCRIPTION OF THE FIGURES

[0049] Further features and advantages of the present invention will be apparent from the following description of a non-limiting embodiment thereof , with reference to the Figures of the accompanying drawings , wherein :

[0050] - Figure 1 is a schematic view, with parts removed for clarity and schematized parts , o f a system for trans ferring resources in a body of water to an unmanned underwater vehicle provided in accordance with the present invention and in an operative configuration;

[0051] - Figure 2 is a sectional view, with parts removed for clarity and schemati zed parts , of the system in Figure 1 in a launch and recovery configuration;

[0052] - Figure 3 is a sectional view, with parts removed for clarity and schemati zed parts , of a surface station of the system in Figure 1 ;

[0053] - Figure 4 is a sectional view, with parts removed for clarity and schemati zed parts , of a detail of the surface station in Figure 3 ;

[0054] - Figure 5 is a sectional view, with parts removed for clarity and schemati zed parts , of an underwater station of the system in Figure 1 ;

[0055] - Figure 6 is a sectional view, with parts removed for clarity and schemati zed parts , of a detail of the underwater station in Figure 5;

[0056] - Figure 7 is a sectional view, with parts removed for clarity and schematized parts, of a depth buoy of the system in Figure 1; and

[0057] - Figures 8-11 are sectional views, with parts removed for clarity and schematized parts, of the system in Figure

[0058] 1 in respective installation steps. DETAILED DESCRIPTION OF THE FIGURES

[0059] With reference to Figures 1 and 2, the numeral 1 indicates, as a whole, a system for transferring resources in a body of water 2 to an unmanned underwater vehicle 3. The system 1 comprises a floating surface station 4, which is configured to generate electrical energy and transceive data; an underwater station 5 which can be connected to the underwater vehicle 3; a depth buoy 6; and an umbilical 7, which comprises at least one power transmission line and at least one data transmission line (not shown in the attached figures) and connects electrically and for data exchange the surface station 4 to the underwater station 5 via the depth buoy 6.

[0060] In particular, the system 1 is configured to selectively assume in the body of water 2 a launch and recovery configuration (Figure 2) , in which the surface station 4, the depth buoy 6 and the underwater station 5 are mechanically joined to form a single assembled body 45; and an operative configuration (Figure 1) , in which the underwater station 5 is laid on a bed 8 of the body of water

[0061] 2 and the depth buoy 6 is placed at a specified depth in the body of water 2 at a distance from the underwater station 5 and from the surface station 4.

[0062] With reference to Figure 1, the system 1 is shown in the operative configuration . In this configuration, the umbilical 7 has a section 9 forming a catenary between the surface station 4 and the depth buoy 6 , and a section 10 extending taut between the depth buoy 6 and the underwater station 5 .

[0063] In particular, the umbilical 7 is configured to transmit power and data and is stably connected to the underwater station 5 and the surface station 4 so as to transmit the power generated in the surface station 4 to users connected to the underwater station 5 and transmit data between the underwater station 5 and the surface station 4 .

[0064] In addition, the system 1 comprises an unmanned underwater vehicle 3 , which is in communication with the underwater station 5 for data exchange . In particular, the underwater vehicle 3 is configured to monitor and / or support the operations for installing the system 1 .

[0065] In the non-limiting case of the present invention described and illustrated herein, the system 1 comprises a lightweight cable 11 connected electrically and for data exchange to the underwater station 5 and to the underwater vehicle 3 . In this configuration, the underwater vehicle 3 is of the ROV type .

[0066] In accordance with one embodiment not shown in the attached Figures , the underwater vehicle 3 may include a battery for power supply and is configured to operate autonomously from the underwater station 5 . In this configuration, the underwater vehicle 3 is of the AUV type and does not require a cable for electrical connection and data exchange with the underwater station 5 .

[0067] In accordance with a further embodiment not shown in the attached Figures , the underwater vehicle 3 comprises an operating module , which can be coupled to / uncoupled from the underwater vehicle 3 and is provided with a cable connected electrically and for data exchange to the underwater station 5 and with a device for managing said cable . In this configuration, when this operating module is coupled to the underwater vehicle 3 , the underwater vehicle 3 operates in ROV mode . On the other hand, when said module is uncoupled from the underwater vehicle 3 , the underwater vehicle 3 operates in AUV mode .

[0068] In particular, the system 1 is controlled by a control station 12 , which in the case illustrated in Figure 1 is shown for simplicity on board a support vessel 13 but which can be located in a remote position, for example on a nearby platform or on land .

[0069] In further detail , the surface station 4 is configured to communicate wirelessly, preferably via antennas , with the control station 12 in order to exchange data with the control station 12 .

[0070] With reference to Figure 2 , the system 1 is shown in the launch and recovery configuration . In this configuration, the surface station 4 , the depth buoy 6 and the underwater station 5 form a single assembled body 45 . In other words , the surface station 4 , the depth buoy 6 and the underwater station 5 are coupled integrally to each other .

[0071] In particular, the depth buoy 6 is located between the surface station 4 and the underwater station 5 and rigidly connects the surface station 4 to the underwater station 5 .

[0072] With reference to Figure 3 , the surface station 4 comprises a support structure 14 and a generator unit 15 , which is housed in the support structure 14 and is configured to produce electrical energy . In the case shown herein, the generator unit 15 comprises an electric generator driven by an internal combustion engine . In accordance with alternative embodiments , not shown in the attached Figures , the generator unit 15 comprises fuel cells or a wind turbine or solar cells or a wave turbine .

[0073] The surface station 4 may also include a dynamic steering device , not shown in the attached Figures , which allows the surface station 4 to be maintained in a given orientation, in particular so as to prevent rotations of the section 9 of the umbilical 7 ( Figure 1 ) when weather and sea conditions change in any operational step . In particular, the dynamic steering device allows the rotation of the surface station 4 to be prevented so as to limit the twisting of the section 9 of the umbilical 7 ( Figure 1 ) .

[0074] The dynamic steering device compri ses adj ustable screw propellers , and a control unit configured to control the power and orientation of the propellers according to the signals detected by the detection system .

[0075] In accordance with the present invention, the surface station 4 comprises a mechanical connector 16 .

[0076] With reference to Figure 4 , the mechanical connector 16 comprises a housing cylinder 17 configured to house a cylindrical body of an additional connector, and a locking mechanism 18 configured to selectively retain / release said cylindrical body in / from the housing cylinder 17 .

[0077] In further detail , the locking mechanism 18 comprises a locking cam 19 , commonly referred to as a j aw, which is coupled to the housing cylinder 17 so that it can rotate between a locking position, in which the locking cam 19 retains the cylindrical body of an additional connector within the housing cylinder 17 , and a release position, in which the locking cam 19 allows said cylindrical body to be released from the housing cylinder 17 ; and a control actuator 20 , which is configured to control the rotation of the locking cam 19 and preferably includes a hydraulic cylinder .

[0078] In particular, the locking mechanism 18 comprises a plurality of locking cams 19 and a plurality of control actuators 20 , each of which is associated with a respective locking cam 19 . In the non-limiting case of the present invention described and illustrated herein, the locking mechanism 18 comprises three locking cams 19 and three control actuators 20 .

[0079] With reference to Figure 5 , the underwater station 5 comprises a support structure 21 , which is configured to be laid on the bed 8 of the body of water 2 , and a housing base 22 configured to allow the sheltering and / or charging of the underwater vehicle 3 .

[0080] In accordance with the present invention, the underwater station 5 comprises a winch 23 conf igured to selectively unwind / wind the umbilical 7 so as to adj ust a length of the sections 9 and 10 of the umbilical 7 .

[0081] In particular, the winch 23 is coupled to an end portion of the support structure 21 and comprises a drum 24 around which a portion of the umbilical 7 is wound .

[0082] In the non-limiting case of the present invention described and illustrated herein, the underwater station 5 comprises a plurality of guide pul leys 25 arranged so as to redirect the umbilical 7 in order to keep the section 10 aligned with the centre of gravity of the underwater station 5 .

[0083] In addition, the underwater station 5 comprises a mechanical connector 26 .

[0084] With reference to Figure 6 , the mechanical connector 26 comprises a housing cylinder 27 configured to house a cylindrical body of an additional connector, and a locking mechanism 28 configured to selectively retain / release said cylindrical body in / from the housing cylinder 27 .

[0085] In further detail , the locking mechanism 28 comprises a locking cam 29 , commonly referred to as a j aw, which is coupled to the housing cylinder 27 so that it can rotate between a locking position, in which the locking cam 29 retains the cylindrical body of an additional connector within the housing cylinder 27 , and a release position, in which the locking cam 29 allows said cylindrical body to be released from the housing cylinder 27 ; and a control actuator 30 , which is configured to control the rotation of the locking cam 29 and preferably includes a hydraulic cylinder .

[0086] In particular, the locking mechanism 28 comprises a plurality of locking cams 29 and a plurality of control actuators 30 , each of which is associated with a respective locking cam 29 . In the non-limiting case of the present invention described and illustrated herein, the locking mechanism 28 comprises three locking cams 29 and three control actuators 30 .

[0087] With reference to Figure 7 , the depth buoy 6 extends around the umbilical 7 and has a through opening 31 , within which a portion of the umbilical 7 is housed . In other words , the through opening 31 allows the umbilical 7 to sl ide within the depth buoy 6 .

[0088] In particular, the depth buoy 6 comprises a floating body 32 , which is configured to provide the depth buoy 6 with an upward hydrostatic thrust when the depth buoy 6 is submerged in the body of water 2 . In other words , the depth buoy 6 has a positive hydrostatic attitude . In this case , the floating body 32 is arranged around a portion of the umbilical 7 .

[0089] In accordance with the present invention, the depth buoy 6 comprises a mechanical connector 33 configured to selectively couple to / uncouple from the mechanical connector 16 of the surface station 4 so as to mechanically connect / disconnect the surface station 4 to / from the depth buoy 6 ; and a mechanical connector 34 configured to selectively couple to / uncouple from the mechanical connector 26 of the underwater station 5 so as to mechanically connect / disconnect the underwater station 5 to / from the depth buoy 6 .

[0090] In particular, each mechanical connector 33 , 34 comprises a respective cylindrical body 35 , 36 configured to be housed within the respective housing cylinder 17 , 27 . In further detail , each cylindrical body 35 , 36 has a respective through opening 37 , 38 to allow the umbilical 7 to slide freely within the mechanical connectors 33 and 34 .

[0091] Furthermore , the depth buoy 6 comprises a locking assembly 39 configured to selectively bind / unbind the depth buoy 6 to / from the umbilical 7 .

[0092] In particular, the locking assembly 39 comprises a clamp 40 fitted with j aws (not shown in the attached Figures ) which can move between an open position, in which the aws allow the umbilical 7 to slide in relation to the locking assembly 39 , and a closed position, in which the j aws bind the locking assembly 39 to a portion of the umbilical 7 . In other words , in the closed pos ition, the j aws tighten the umbilical 7 and friction lock the sliding of the umbilical 7 in relation to the depth buoy 6 .

[0093] In further detail , the locking assembly 39 comprises a passive actuation mechanism 42 , which is configured to control the position of the j aws . In particular, the actuation mechanism 42 comprises a control linkage 43 configured to cooperate with the mechanical connector 26 of the underwater station 5 so that , when the mechanical connector 26 is coupled to the mechanical connector 34 , the control linkage 43 keeps the aws in the open position . Vice versa, when the mechanical connector 26 is uncoupled from the mechanical connector 34 , the control linkage 43 is configured to keep the j aws in the closed position .

[0094] In use and with reference to Figure 8 , the system 1 is arranged in the launch and recovery configuration and transported on board the support vessel 13 to an installation site .

[0095] Upon reaching the installation site , the system 1 is li fted by a launch and recovery crane 44 of the support vessel 13 and launched into the body of water 2 .

[0096] With reference to Figure 9 , the mechanical connector 33 is uncoupled from the mechanical connector 16 in order to uncouple the depth buoy 6 from the surface station 4 .

[0097] At this point , the winch 23 deploys the section 9 of the umbilical 7 in order to lower the assembly cons isting of the depth buoy 6 and underwater station 5 into the body of water 2 , towards the bed 8 of the body of water 2 , while the surface station 4 remains floating on the surface .

[0098] With reference to Figure 10 , when the depth buoy 6 and the underwater station 5 reach a speci fied depth in the body of water 2 , the mechanical connector 34 is uncoupled from the mechanical connector 26 . The uncoupling of the mechanical connectors 34 and 26 causes , by activating the actuation mechanism 42 , the j aws to close around the umbilical 7 such as to bind the depth buoy 6 to the umbilical 7 at a speci fied distance from the surface station 4 .

[0099] At this point , the winch 23 deploys the section 10 of the umbilical 7 in order to lower the underwater station 5 onto the bed 8 of the body of water 2 and arrange the system

[0100] 1 in the operative configuration .

[0101] With reference to Figure 11 , once the underwater station 5 is laid on the bed 8 of the body of water 2 , the launch and recovery crane 44 is uncoupled from the surface station 4 .

[0102] Next , the winch 23 deploys the umbilical 7 . Since the depth buoy 6 has a positive hydrostatic attitude , the depth buoy 6 moves towards the surface of the body of water 2 keeping the section 10 of the umbilical 7 taut and the section 9 of the umbilical 7 slack to form a correct catenary geometry .

[0103] In practice , the winch 23 is used to lower the depth buoy 6 and the underwater station 5 into the body of water

[0104] 2 and to adj ust the length of the sections 9 and 10 of the umbilical 7 and the depth of the depth buoy 6 .

[0105] In particular, the length of the section 10 of the umbilical 7 is selected so that the depth buoy 6 is preferably located at a depth within the range between 30 and 70 metres from the surface of the body of water 2 . The length of the section 9 of the umbilical 7 is selected so that it is considerably greater than the depth of the depth buoy 6 .

[0106] In accordance with one embodiment not shown in the attached Figures , during the installation of the system 1 , the underwater vehicle 3 exits the housing base 22 , navigates the body of water 2 and monitors and / or supports the operations for installing the system 1 .

[0107] With reference to Figure 1 , when the system 1 is installed and in its operative configuration, the surface station 4 generates electrical energy through the generator unit 15 and exchanges signals with the control station 12 . Via the umbilical 7 , the surface station 4 transmits electrical energy to the underwater station 5 and exchanges data with the underwater station 5 , which in turn is connected to the underwater vehicle 3 to supply power and exchange data .

[0108] Lastly, it is clear that variations from the embodiments described above may be made to the present invention without however departing from the scope of protection of the appended claims .

Claims

CLAIMS1. A system for transferring resources in a body of water to an unmanned underwater vehicle, the system (1) comprising :- a floating surface station (4) , which is configured to generate electrical energy and transceive data;- an underwater station (5) connectable to at least one unmanned underwater vehicle (3) ;- a depth buoy (6) ; and- an umbilical (7) , which comprises at least one power transmission line and at least one data transmission line and connects electrically and for data exchange the surface station (4) to the underwater station (5) via the depth buoy (6) ; the system (1) being configured to selectively assume in the body of water (2) :- a launch and recovery configuration, in which the surface station (4) , the depth buoy (6) and the underwater station (5) are mechanically joined to form a single assembled body (45) ;- an operative configuration, in which the underwater station (5) is laid on a bed (8) of the body of water (2) and the depth buoy (6) is placed at a specified depth in the body of water (2) at a distance from the underwater station (5) and from the surface station (4) .

2. The system as claimed in Claim 1, wherein the surface station (4) comprises a first mechanical connector (16) ; the depth buoy (6) comprising a second mechanical connector (33) configured to selectively couple to / uncouple from the first mechanical connector (16) so as to mechanically connect / disconnect the surface station (4)to / from the depth buoy (6) .

3. The system as claimed in Claim 1 or 2, wherein the underwater station (5) comprises a third mechanical connector (26) ; the depth buoy (6) comprising a fourth mechanical connector (34) configured to selectively couple to / uncouple from the third mechanical connector (26) so as to mechanically connect / disconnect the underwater station (5) to / from the depth buoy (6) .

4. The system as claimed in any one of the foregoing Claims, wherein the depth buoy (6) comprises a locking assembly (39) configured to selectively bind / unbind the depth buoy (6) to / from the umbilical (7) .

5. The system as claimed in Claim 4, wherein the depth buoy (6) extends around the umbilical (7) and has a through opening (31) , within which a portion of the umbilical (7) is housed .

6. The system as claimed in any one of the foregoing Claims, wherein in the operative configuration the umbilical (7) has a first section (9) extending between the surface station (4) and the depth buoy (6) , and a second section (10) extending between the depth buoy (6) and the underwater station ( 5 ) .

7. The system as claimed in Claim 6, wherein the underwater station (5) comprises a winch (23) configured to selectively unwind / wind the umbilical (7) so as to adjust a length of the first and / or the second section (9, 10) of the umbilical ( 7 ) .

8. The system as claimed in any one of the foregoing Claims, and comprising an unmanned underwater vehicle (3) and a cable (11) connected electrically and for data exchange to the underwater station (5) and to the unmanned underwatervehicle ( 3 ) .

9. The system as claimed in Claim 8, wherein the underwater station (5) comprises a housing base (22) configured to allow the sheltering and / or charging of the unmanned underwater vehicle (3) .

10. The system as claimed in any one of the foregoing Claims, and comprising a support vessel (13) provided with a control station (12) , which is in communication with the surface station (4) , and a launch and recovery crane (44) , which is configured to launch and recover the system (1) in the launch and recovery configuration.

11. An installation method for installing a system for transferring resources in a body of water as claimed in any one of the foregoing Claims, the installation method comprising the steps of:- arranging the system (1) in the launch and recovery configuration, in which the surface station (4) , the depth buoy (6) and the underwater station (5) are mechanically joined to form a single assembled body (45) ;- launching into the body of water (2) the system (1) in the launch and recovery configuration;- uncoupling the surface station (4) from the depth buoy (6) and the underwater station (5) ;- deploying a first section (9) of the umbilical (7) so as to lower the depth buoy (6) and the underwater station (5) into the body of water (2) ;- uncoupling the underwater station (5) from the depth buoy ( 6 ) ;- binding the depth buoy (6) to the umbilical (7) at a distance from the surface station (4) ; and- deploying a second section (10) of the umbilical (7)so as to lower the underwater station (5) onto the bed (8) of the body of water (2) .

12. The installation method as claimed in Claim 11, and comprising the step of deploying the second section (10) of the umbilical (7) so as to increase the distance between the depth buoy (6) and the underwater station (5) and making the first section (9) of the umbilical (7) slack when the underwater station (5) is placed on the bed (8) of the body of water ( 2 ) .

13. The installation method as claimed in Claim 11 or 12, and comprising the step of unwinding the umbilical (7) by means of a winch (23) of the underwater station (5) to deploy the first and / or the second section (9, 10) of the umbilical ( 7 ) .

14. The installation method as claimed in any one of Claims 11 to 13, and comprising the steps of housing an unmanned underwater vehicle (3) in the underwater station (5) ; transferring power and data between the underwater station (5) and the unmanned underwater vehicle (3) ; and controlling a navigation of the unmanned underwater vehicle (3) in the body of water (2) .

15. The installation method as claimed in Claim 14, and comprising the step of monitoring and / or supporting the operations for installing the system (1) by means of said underwater vehicle (3) .

16. The installation method as claimed in any one of Claims 11 to 15, and comprising the step of transporting the system (1) in the launch and recovery configuration in the body of water (3) from a first installation site to a second installation site aboard a support vessel (13) .

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