Patent Publication Number: US-2020298943-A1

Title: System and method for preventing fouling and/or corrosion on vessels and marine objects

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International patent application No. PCT/AU2018/051307, filed on Dec. 6, 2018 and titled SYSTEM AND METHOD FOR PREVENTING FOULING AND/OR CORROSION ON VESSELS AND MARINE OBJECTS (“the &#39;307 PCT Application”). The &#39;307 PCT Application includes a claim for the benefit of priority to the Dec. 6, 2017 filing date of Australian Provisional Patent Application No. 2017904918, titled SYSTEM AND METHOD FOR PREVENTING FOULING AND/OR CORROSION ON VESSELS AND MARINE OBJECTS (“the &#39;918 Australian Provisional Application”). The entire disclosures of the &#39;307 PCT Application and the &#39;918 Australian Provisional Application are hereby incorporated herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the prevention of fouling and/or corrosion on objects in an aquatic environment. 
     BACKGROUND 
     Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge. 
     Barnacles, algae, and marine organisms often build up on underwater structures, such as hulls of boats, which process is generally referred to as biological fouling. In the case of boats, the presence of fouling may increase resistance (drag) in the water, which in turn increases fuel consumption. Fouling can, however, also cause damage to the hull or propulsion system. Similar problems exist with other underwater structures, such as subsea machinery. 
     Anti-fouling coatings are often applied to these underwater structures to prevent, or at least reduce the prevalence of fouling. In many cases paints including biocides are applied to the hull of boats and ships to prevent such fouling. A problem with such anti-fouling coatings is that they are often toxic to the marine environments in which they are used. In particular, the anti-fouling coatings generally wear off, and thus become distributed in waterways where they may cause damage to other types of marine life. A further problem with such anti-fouling coatings is that they are generally difficult to apply, as the boat (or other structure) must come out of water for such application. While it is possible to apply such coatings at time of manufacture, the coatings must generally be re-applied periodically. 
     Another problem with underwater structures is corrosion. Often paint, or similar anti-corrosion coatings, are provided on underwater structures to prevent corrosion. Similar problems, however, exist in relation to anti-corrosion coatings as are discussed above in relation to anti-fouling coatings. 
     As such, there is clearly a need for an improved system for preventing fouling and/or corrosion on objects in an aquatic environment. 
     SUMMARY 
     In an aspect, the invention provides a corrosion or fouling prevention system for preventing the fouling or corrosion of a vessel or an aquatic object having a surface in contact with seawater and/or brackish water in an aquatic environment, the system comprising: 
     a flexible and non-permeable barrier that extends about a surface of the vessel or aquatic object to avoid direct contact between the surface and the seawater and/or brackish water, 
     an attachment structure for attachment of the barrier relative to the vessel or aquatic object to position the barrier in a spaced apart arrangement from the surface of the vessel to define an internal volume in between the surface of the vessel of the object and the barrier to receive a fluid that has a composition that is different to the aquatic environment. 
     In an embodiment, the attachment structure comprises one or more floatation devices adapted for being positioned relative to the vessel or object and wherein during use the barrier is suspended in a generally downward direction relative to the floatation device to position the barrier in said spaced apart arrangement. 
     In an embodiment, buoyancy of the one or more floatation devices may be variable to allow the lowering or raising of the attachment structure. 
     In an embodiment, the floatation devices are adapted to be attached to the vessel or object. 
     In an embodiment, the floatation device comprises walls enclosing a hollow cavity with an inlet for receiving a fluid therein such that supplying fluid into the cavity of the floatation device results in lowering or submerging the attachment structure into the seawater and/or brackish water in a lowered position to allow said vessel or aquatic object to be positioned above the attachment structure; and a fluid removal arrangement to gradually remove fluid from the one or more cavities of the floatation device to raise the attachment structure to the surface of the seawater or brackish water to facilitate attachment of the barrier relative to the vessel or aquatic object. 
     In an embodiment, the corrosion or fouling prevention system further comprises a flow controller for controlling the flow of fluid into or out of the one or more cavities of the floatation devices thereby effecting movement of the attachment structure. 
     In an embodiment, the corrosion or fouling prevention system further comprises: 
     a pumping arrangement adapted to pump out sea water or brackish water from the internal volume in between the surface of the vessel of the object; and 
     a fluid supply arrangement to supply the fluid that has a composition that is different to the aquatic environment into the internal volume in between the surface of the vessel of the object. 
     In an embodiment, the corrosion or fouling prevention system further comprises one or more coupling assemblies positioned relative to the barrier and/or the attachment structure, said coupling assemblies being adapted to be coupled to the pumping arrangement and/or the fluid supply arrangement. 
     In an embodiment, the flotation devices further comprise one or more vents positioned to vent the cavities and release accumulation of air when the floatation devices contain pressurised fluid in the one or more cavities. 
     In an embodiment, the corrosion or fouling prevention system for preventing the fouling or corrosion of a vessel having a surface in contact with seawater and/or brackish water in an aquatic environment further comprises a marina attachment assembly adapted to be coupled with the attachment structure and/or the barrier to facilitate installation or removal of the corrosion or fouling prevention system relative to the vessel. 
     In an embodiment, the marina attachment assembly further comprises an extension member extending outwardly from the marina for attachment to the attachment structure at one or more attachment locations wherein the extension member is adapted for movement in an upward or downward to facilitate upward or downward movement of the attachment structure relative to the vessel thereby facilitating installation or removal of the corrosion or fouling prevention system relative to the vessel. 
     In an embodiment, the marina attachment assembly comprising one or more connectors adapted to be fluidly coupled to the fluid supply arrangement and the pumping arrangement. 
     In an embodiment, the fluid received in the internal volume in between the surface of the vessel of the object and the barrier is fresh water. 
     In an embodiment, the corrosion or fouling prevention system further comprises a sealing arrangement for sealing a portion of the barrier relative to the vessel or the marine object to prevent the sea water or brackish water from being received into the internal volume in between the surface of the vessel of the object and the barrier. 
     In another aspect, the invention provides a method for corrosion or fouling prevention in a vessel or an aquatic object having a surface in contact with seawater and/or brackish water in an aquatic environment, the method comprising:
         a. positioning a flexible and non-permeable barrier that extends about a surface of the vessel or aquatic object to avoid direct contact between the surface and the seawater and/or brackish water;   b. attaching an attachment structure relative to the vessel or aquatic object to position the barrier in a spaced apart arrangement from the surface of the vessel to define an internal volume in between the surface of the vessel of the object and the barrier; and   c. supplying a fluid into the internal volume wherein the fluid has a composition that is different to the aquatic environment.       

     In an embodiment, the attachment structure comprises one or more floatation devices adapted for attachment to the vessel or object and wherein the attachment step of the method comprises suspending the barrier in a generally downward direction relative to the floatation device to position the barrier in said spaced apart arrangement. 
     In an embodiment, the method for corrosion or fouling prevention further comprises the steps of:
         d. supplying fluid into a hollow cavity defined by walls of the floatation devices to lower or submerge the attachment structure into the seawater and/or brackish water into a lowered position to allow said vessel or aquatic object to be positioned above the attachment structure; and   e. remove or pump fluid out of the hollow cavity of the floatation devices to gradually raise the floatation devices of the attachment structure to the surface of the seawater or brackish water for facilitating positioning of the barrier relative to the vessel or aquatic object.       

     In an embodiment, the method for corrosion or fouling prevention further comprises an intermediate step of: pumping or removing any sea water or brackish water from the internal volume before the step of supplying the fluid into the internal volume in between the surface of the vessel of the object and the barrier. 
     In an embodiment, the method further comprises the step of coupling the attachment structure and/or the barrier to a marina attachment assembly to facilitate installation or removal of the corrosion or fouling prevention system relative to the vessel. 
     In an embodiment, the marina attachment assembly further comprises an extension member extending outwardly from the marina and the method comprising the additional steps of:
         attaching the marina attachment assembly to the attachment structure at one or more attachment locations;   lowering the extension member in a downward direction to facilitate downward movement of the attachment structure for positioning the attachment structure in said lowered position before positioning the vessel or aquatic object above the attachment structure;   raising the extension member in an upward direction to facilitate upward movement of the attachment structure in the sea water or brackish water and positioning the attachment structure adjacent the vessel or the object at or along the surface of the sea water or brackish water.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows: 
         FIG. 1  is a section view of a marine vessel  205  being protected by a corrosion and fouling prevention system  200 . 
         FIG. 1A  is an enlarged view of a section  200 A (shown in  FIG. 1 ). 
         FIG. 2  is a side view of the vessel  205  with the corrosion and fouling prevention system  200  installed thereon shown in an in-use configuration. 
         FIG. 3  is a sectional view of the marine vessel  205  with the corrosion protection system  200  shown in a lowered configuration. 
         FIG. 4  is a schematic fluid supply and pumping arrangement for either (a) supplying fluid into the floatation device(s)  225  or removing fluid from the floatation devices  225 . 
         FIG. 5  is a sectional view of the marine vessel  205  with the corrosion protection system  200  shown in a gradually raised configuration. 
         FIG. 6  is a sectional view of the marine vessel  205  with the corrosion protection system  200  shown in a fully raised configuration. 
         FIG. 7  is a schematic illustration of a fluid pumping and fluid supplying arrangement for (a) pumping out sea water or brackish water from the internal volume in between the surface of the vessel  205  and the barrier  215 ; and (b) supply protective fluid into the internal volume in between the surface of the vessel of the object. 
         FIG. 8A  is a sectional view of the marine vessel  205  with the corrosion protection system  200  shown in a fully raised configuration whereby the sea water has been pumped out of the internal volume. 
         FIG. 8B  is a sectional view of the marine vessel  205  with the corrosion protection system  200  shown in a fully raised configuration whereby the protective fluid has been pumped into the internal volume. 
         FIG. 9  is a side view of the vessel  205  with the corrosion and fouling prevention system  200  installed thereon shown in a coupled configuration relative to a marine attachment assembly  235 . 
         FIG. 10  is a top view of the corrosion and fouling prevention system  200  (marine vessel  205  removed for clarity) shown in a coupled configuration relative to a marine attachment assembly  235 . 
         FIG. 11  is a side view of the corrosion and fouling prevention system  200  (marine vessel  205  removed for clarity) in a lowered configuration shown as coupled to a marine attachment assembly  235 . 
         FIG. 12  is a side view of the corrosion and fouling prevention system  200  (marine vessel  205  removed for clarity) in a raised configuration shown as coupled to a marine attachment assembly  235 . 
         FIG. 13  is a schematic illustration of the master controller  230  shown in communication with the first and second controllers  273  and  287 . 
         FIG. 14  illustrates a side view of a system for preventing fouling and/or corrosion on a buoy in the sea  410 , according to an embodiment of the present invention; 
         FIG. 15  illustrates a side view of a system for preventing fouling and/or corrosion on subsea machinery in the sea, according to an embodiment of the present invention; 
         FIG. 16  illustrates a schematic of a system for preventing fouling and/or corrosion on an object which is partially submerged in an aquatic environment, according to an embodiment of the present invention; 
         FIG. 17  illustrates a schematic of a system for preventing fouling and/or corrosion on an object which is fully submerged in an aquatic environment, according to an embodiment of the present invention; and 
         FIG. 18  illustrates a schematic of a system for preventing fouling and/or corrosion on an object which is partially submerged extending in an aquatic environment extending into the earth base, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 to 13  illustrate a corrosion and fouling prevention system  200  for preventing the fouling or corrosion of a vessel  205 . In particular, the system  200  protects the hull of the vessel  205  and is provided to protect the vessel  205  from growth of barnacles, algae, and marine organisms thereon, and corrosion, both of which may otherwise occur if the vessel  205  was submerged in an aquatic environment  210 , without protection. The aquatic environment  210  is generally an exposed body of water, such as a sea, river or lake, which contains barnacles, algae, and/or marine organisms. 
     The system  200  includes a flexible and non-permeable sheet  215  which is positioned near the hull of the vessel  205  to form a barrier and define a protection zone  220  adjacent to the vessel  205 . During use, the sheet  215  extends about a surface of the hull  205   a  of the vessel  205  to avoid direct contact between the surface  205   a  and the seawater and/or brackish water of the aquatic environment  210 . 
     Floatation devices  225  include attachment structures to allow attachment of the floatation devices  225  to the vessel  205  at a plurality of locations extend around the surface of the hull  205   a . The floatation devices  225  allow the non-permeable sheet  215  to be positioned in a spaced apart configuration relative to the surface  205   a  of the hull to define an internal volume in between the surface of the vessel  205   a  and the sheet/barrier  215  to receive a fluid that has a composition that is different to the aquatic environment. In an in-use configuration, the internal volume in between the surface of the vessel  205   a  and the sheet/barrier  215  is filled with a protective fluid (e.g. fresh water) which is different to the seawater or brackish water of the aquatic environment  210 . 
       FIG. 1A  depicts an enlarged sectional view of a section  200 A from  FIG. 1 . The aquatic environment  210  may comprise an ocean or a water body that is likely to promote growth of barnacles, algae, and marine organisms on the hull surface  205   a  of the vessel  205  and cause damage thereto, or at least increase drag in the boat, which may increase fuel consumption. Similarly, without protection, metallic items on or around the hull  205  may undergo corrosion. The applicant has found that attachment of the floatation devices  225  around the hull  205   a  of the vessel to suspend the barrier sheet  215  in a generally downward direction and filling the internal volume between the surface of the vessel  205   a  and the sheet/barrier  215  with the protective fluid (having a composition that prevents or inhibits corrosion and fouling of the hull surface  205   a ) results in the formation of the protection zone  220  that prevents fouling and corrosion of the boat  205 . 
     The system  200  is preferably reusable, in that it can be opened or removed when the boat  205  is underway, and closed or reinstalled when the boat  205  is moored or anchored as will be explained in the foregoing sections. 
     The floatation device(s)  225  comprise a substantially hollow structure. In the presently described embodiment, the floatation devices(s)  225  take the form of hollow pipes (such as PVC pipes) comprising walls that enclose a hollow cavity for receiving a fluid into the hollow cavity. Referring to  FIGS. 3 and 4 , the floatation devices  225  are provided with respective fluid inlets  227  for allowing fluid to be filled into the cavities of the floatation devices  225 . Each of the inlets  227  may be fluidly coupled with a pumping arrangement comprising a pumping device  270  controlled by a flow controller  273 . The controller  273  may be actuated by a user in an initial step to pump a fluid such as fresh water using the pumping device  270  into the floatation devices  225 . The fluid may be pumped from a reservoir  275 . Supplying fluid into the cavity of the floatation device(s)  225  results in lowering or submerging the floatation devices  225  into the seawater and/or brackish water in a lowered position to allow the vessel  205  to be positioned above the corrosion and fouling prevention system  200 . As evident from  FIG. 3 , lowering the floatation device  225  temporarily (by supplying fluid into the hollow floatation devices  225 , as explained above) allows the vessel  205  to be moored into an initial position for installation whereby the vessel  205  is directly above the floatation devices. It is also important to note that during this initial installation step, sea water or brackish water from the aquatic environment  210  may enter the internal volume defined by the barrier sheet  215 . The removal of this sea water or brackish water from the internal volume of the barrier sheet  215  will be discussed in the following sections. 
     Once the vessel  205  has been positioned substantially above the floatation devices (initial position- FIG. 3 ), water from the floatation devices  225  may be raised relative to the vessel  205  by removing fluid from the floatation devices  225 . Once again the fluid inlets  227  may now be utilised for directing the fluid out of the floatation devices  225 . Gradual removal of the fluid from the floatation devices  225  may be carried out by actuating the controller  273  to pump fluid out of the floatation devices  225  using the pumping device  270  to feed the pumped fluid back into the reservoir  275 .  FIG. 5  depicts the floatation devices  225  in a gradually raised configuration. 
     Referring to  FIG. 6 , once the fluid from the floatation devices  225  has been substantially pumped out or removed, the floatation devices  225  rise and become positioned at the surface of the sea water or brackish water in close proximity to the hull of the vessel  205 . One or more vents  225  (See  FIGS. 11 and 12 ) may be positioned to vent the cavities of the floatation devices  225  and release accumulation of air if the floatation devices  225  contain pressurised fluid in the one or more cavities. 
     The floatation device(s)  225  may be fastened or attached to the hull of the vessel at a plurality of attachment locations. The manner in which the floatation device(s) are fastened to the vessel  205  is not limiting and one or more conventional methods may be used for attachment of the floatation devices  225  to the vessel  205 . In some embodiments, the attachment of the floatation device(s) to the vessel  205  may result in forming a sealing arrangement for sealing a portion of the sheet or barrier  215  relative to the vessel  205 . Formation of such a seal allows the internal volume defined in between the surface of the vessel  205  and the barrier  215  to be fluidly sealed relative to the aquatic environment  210 . 
     Upon attachment of the floatation devices  225  and formation of the sealing arrangement, the next step involves removal of any sea water or brackish water from the internal volume defined in between the surface of the vessel  205  and the barrier  215 . A fluid inlet/outlet  217  is provided for removal of fluid from the substantially sealed internal volume. It must be understood that the location or structural configuration of the inlet/outlet  217  is not limiting. A secondary controller  287  may be actuated to commence a pumping operation that results in the sea water or brackish water being pumped out of the internal volume. Another pumping device  280  may be used for pumping out the sea water and directing the sea water into a reservoir  283 . Alternatively, the pumped sea water may also be released into the aquatic environment  210 .  FIG. 8A  depicts the system  200  in an emptied configuration (without any protective fluid in the internal volume). 
     Once the sea water has been removed from the internal volume, the protective fluid may be pumped into the internal volume by actuating the controller  287 . Actuating the controller  287  results in the protective fluid being pumped from a protective fluid reservoir  285  into the internal volume defined by the barrier sheet  215  by introducing the protective fluid into the internal volume through the inlet/outlet  217  to form the protective zone  220  as shown in  FIG. 8B . 
     Referring to  FIGS. 9 to 12 , the system  200  also comprises a marina attachment assembly  235  that is adapted to be coupled with the floatation devices  225  and the barrier sheet  215  to facilitate installation or removal of the corrosion or fouling prevention system  200  on the marine vessel  205 . The marina attachment assembly  235  includes an extension member  238  extending outwardly from the marina M for attachment to the attachment structures of the floatation devices  225  at an attachment location such as attachment location  239  (See  FIGS. 11 and 12 ). The extension member  237  is substantially elongate and pivots about a pivot point  237  to allow the distal end of the extension member  238  to be lowered or raised when the extension member  238  is pivoted about the pivot point  237 . The marina attachment assembly  235 , particularly the extension member  238  assists with the lowering or raising of the floatation devices  225  (attached to the extension member at attachment location  239 ) during installation of the corrosion and fouling prevention system  200  onto the vessel  205 . Similarly, the marina attachment assembly  235 , particularly the extension member  238  also assists with the lowering or raising of the floatation devices  225  (attached to the extension member at attachment location  239 ) during removal of the corrosion and fouling prevention system  200  from the vessel  205 .  FIG. 11  shows the system  200  in a lowered position whilst being coupled to the marina attachment assembly  235 .  FIGS. 9 and 12  on the other hand shows the system  200  in a raised configuration whilst being coupled to the marina attachment assembly  235 . 
     The marina attachment assembly  235  may also provide one or more supply lines via a services hub  240  for supplying electricity and for supplying the protective fluid (e.g., fresh water) and other fluids (such as fluids pumped into the floatation devices  225 ). Additional supply lines may also be provided via a secondary hub  245 . By way of example, the secondary hub  245  may be used for pumping out sea water or brackish water out of the internal volume of the barrier  215  (as shown in  FIG. 8A ). 
     Additional fluid couplings or connection points  243  and associated controllers may also be provided for providing additional control over fluid flow into and out of the floatation devices  225 . 
     As shown in  FIG. 13 , the first controller  273  (that controls the fluid filling or fluid removal from the floatation devices  225 ) and the second controller  287  (that controls pumping out of sea water out of the internal volume of the barrier and filling the internal volume with protective fluid) may be electronically coupled to a master controller  230  (See  FIGS. 9, 10 and 13 ). Furthermore, the master controller in at least some embodiments, may be positioned relative to the marina attachment assembly  235  to allow personnel stationed at the marina to easily install or remove the system  200  onto or from the vessel  205 . 
     While the system  200  as described in the previous sections relates to marine vessels  205 , the skilled addressee will readily appreciate that embodiments of the invention may be particularly useful for use around bridge structures which are partially or fully submerged in bodies of water, such as buoys, pylons and subsurface equipment. 
       FIG. 14  illustrates a side view of a system  400  for preventing fouling and/or corrosion on a buoy  405  in the sea  410 , according to an embodiment of the present invention. The buoy  405  is anchored to a sea bottom  410   a  by an anchor  415 . 
     A non-permeable sheet  420  is placed around an underside of the buoy  405  and sealed against the anchor  415  on an underside using attachment  430 , and against a periphery of the buoy  405  and an upper side, defining a protection zone  425  against a submerged portion of the buoy  405 . The seawater is pumped out from the protection zone  425 , and replaced by freshwater in a similar manner as explained in the earlier sections in relation to system  200 . 
     According to certain embodiments, the buoy  405  may be configured to generate freshwater, and thus continuously replenish the freshwater in the protection zone  425 . This is particularly advantageous if the protection zone  425  is not entirely sealed or for example if the sheet used is permeable in one direction only, as it enables nutrients or saltwater to be flushed from the protection zone either continuously or periodically. 
       FIG. 15  illustrates a side view of a system  500  for preventing fouling and/or corrosion on subsea machinery  505  in the sea  510 , according to another embodiment of the present invention. The subsea machinery  505  is associated with an offshore platform  515  and a vessel  520 , which provide above-sea services and control of the machinery  505 . 
     In particular, the machinery  505  is tethered either to the offshore platform  515  or the vessel  520  by a tether  525 . A non-permeable sheet  530  is placed around the machinery  505  and sealed against the tether  525  on one side, and against a periphery of the machinery  505  and an the other side, defining a protection zone  535  around at least part of the machinery  505 . The seawater is pumped out from the protection zone, and replaced by freshwater, as outlined above. 
     Remote Operated Vehicles (ROVs) can be used to install such barriers. The tether  525  may be used to pump the saltwater from the protection zone, and provide the freshwater to the protection zone. The fluid can be displaced via the use of e.g. pumps, pressurized gas cylinders, bottles and compressors. Relevant fluid can be placed, replaced, removed or reinstalled into the protection zone  535 , as outlined above. If the fluid required in the protective zone is potable water. In this regard, a desalination plant may be located on the offshore platform  515  and/or the vessel  520 , together with pumps and the like, to enable such remote displacement of the saltwater around the machinery  505 . 
       FIG. 16  schematically illustrates a system  600 , for preventing fouling and/or corrosion on an object  1  that is (otherwise) semi-submerged in an aquatic environment  5 , according to an embodiment of the present invention. 
     Much like the systems described above, a barrier  4  is provided adjacent to an underside of the object  1 , which defines a liquid protection zone  2  around an underside of the object. This protects the object  1  from fouling and/or corrosion that would otherwise occur if placed directly in the aquatic environment  5 . Furthermore, one or more devices, switches, valves, pumps and/or electronics  3  exist in the liquid protection zone  2 . 
     An upper side of the object  1  is exposed to atmosphere  7 , and thus does not need protection from the aquatic environment  5 . 
     The barrier  4  may be configured to at least partially float in the aquatic environment  5  when in use, with a lower portion spaced from the earth base  6  of the aquatic environment  5 . The barrier  4  can also be attached to the object  1  directly (e.g. around a periphery thereof), or to one or more other objects. 
     The barrier  4  may also transition between a raised and a lowered state. In particular, a portion of the barrier  4  may move or be moved out of the aquatic environment  5  and into the atmosphere  7  (and thus into the raised state), which is particularly useful in case the object  1  is a vessel and is berthed, moored or anchored. The barrier  4  may then be move or be moved back into the aquatic environment  5  (surrounding the object  1 ) (and thus into the lowered state), which is particularly useful when the vessel is in motion or is about to move. 
       FIG. 17  schematically illustrates a system  700 , for preventing fouling and/or corrosion on an object  1  that is (otherwise) submerged in an aquatic environment  5 , according to an embodiment of the present invention. 
     A barrier  4  is provided surrounding the object  1 , which defines a liquid protection zone  2  around the object  1 . This protects the object  1  from fouling and/or corrosion that would otherwise occur if placed directly in the aquatic environment  5 . In contrast to the system  600 , the object  1  is entirely encompassed within the liquid protection zone  2 , and is thus not exposed to atmosphere  7  but is still separated from the earth base  6  of the aquatic environment  5 . 
       FIG. 18  shows a system similar to that illustrated in  FIG. 16  but in which the object  1  extends from above the waterline down into the earth base  6  of the aquatic environment  5 . In this embodiment, the barrier is defined about the object with an upper portion configured to at least partially float in the aquatic environment  5  when in use, and a lower part is either sealed about or extends about a lower end of the object, preferably at least partially within the earth base  6  of the aquatic environment  5 . The barrier  4  can also be attached to the object  1  directly (e.g. around a periphery thereof), or to one or more other objects. 
     While the above embodiments describe use of fresh, clean water, the skilled addressee will readily appreciate that other fluids may be used. As an illustrated example, fluid may comprise a gas (e.g. Carbon Dioxide, Argon or Nitrogen) or a mixture thereof. Preferably, the gas is substantially non-corrosive to the object, and may comprise an inert (or substantially inert) gas or a mixture of gases forming a substantially inert mixture. 
     The use of a gas may enable electrical instruments to be deployed in the area that are unable to function in a liquid, such as an electronic measurement device, relays, switches, sensors and the like. 
     Similarly, the water may comprise seawater (or water from outside of the protection zone) that has been treated with an additive. As an illustrative example, the additive may comprise a biocide and/or a corrosion inhibitor. 
     Furthermore, while the above embodiment describe use of a non-permeable sheet, the skilled addressee will readily appreciate that any suitable barrier may be used, and such barrier may, for example, comprise a plurality of sheets, or any other suitable structure that provides the barrier. In some embodiments, the barrier may include a frame. 
     In some embodiments, the barrier (e.g. a non-permeable sheet) is UV permeable. As such, ultraviolet radiation may penetrate the barrier, which may assist in the prevention of fouling. The barrier is preferably resistant to UV radiation, and as such, does not degrade in the presence of UV radiation. 
     As outlined above, electrical components may be located within the protection zone, including, for example, when the protection zone is filled with a gas. In such case, the barrier may include isolation properties, such as electronic insulation properties, which may prevent interaction of the electrical components with outside components. Furthermore, such barrier may also be provided for the purpose of safety, to further prevent electrical shock or injury to persons or animals in proximity to the barrier. 
     In addition to the objects described above that are made for water, embodiments of the present invention may be used to protect emergency devices in the water. In such case, the barrier may be gas filled, to prevent submersion of the emergency device in the water. 
     Some embodiments of the invention may be specifically configured to prevent cross-contamination between fluid (e.g. fresh water) in the protection zone and fluid (e.g. salt water) outside of the protection zone. As an illustrative example, the water from the protection zone may be retrieved (e.g. by a pump) prior to removal of the protection zone. Similarly, the systems may include the ability to exchange ballast and/or bilge water to prevent cross-contamination between different marine zones. 
     Embodiments described above enable an environment to be quickly and inexpensively created around an object which is at least partially or fully submerged in an aquatic environment, to prevent or reduce fouling, marine growth and/or corrosion (including oxidisation, rust, galvanic corrosion, and change due to electrolysis). As such, the environment around the object may be quickly and efficiently changed from one where marine growth and/or corrosion is sustained, to one where marine growth is not sustained and corrosion is inhibited. 
     The embodiments may be used on structures that are already submerged, and as such, there is no need to retrieve the object from the water, as is the case for anti-fouling painting and/or cleaning. 
     In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. The term “comprises” and its variations, such as “comprising” and “comprised of” is used throughout in an inclusive sense and not to the exclusion of any additional features. 
     It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. 
     The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.