GB2472915A

GB2472915A - Illuminating underwater objects with an ultraviolet light source

Info

Publication number: GB2472915A
Application number: GB1013818A
Authority: GB
Inventors: Cameron J Lawson
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-08-18
Filing date: 2010-08-18
Publication date: 2011-02-23
Anticipated expiration: 2030-08-18
Also published as: GB0914431D0; GB2472915B; GB2472801A; GB201013818D0

Abstract

A method and apparatus for illuminating underwater objects 50 is disclosed, the method comprising: in an underwater environment, directing ultraviolet (UV) light 20 onto the underwater object 50 comprising UV reactive paint, such that the ultraviolet light interacts with the object to produce visible light. The invention may be used in low visibility underwater environments and the reflection of UV light from suspended particles 22 back to the operator does not result in glare because the UV light is invisible. When the UV light reaches the underwater object, such as a wellhead, it produces visible light. In this way the operator may more clearly see the underwater objects they are working with. Can be used on a remotely operated vehicle (ROV) 10 employing camera 16.

Description

Apparatus for Illuminating and Associated Methods

Technical Field

This invention relates to apparatus and methods for illuminating underwater objects. In particular, but not exclusively, the invention relates to apparatus and methods for illuminating underwater objects such as those used in the oil and gas industry.

Background

When conducting subsea activities it is helpful to light objects or equipment being worked on in order to enable a diver or operator of a remotely operated vehicle (ROV) to see what they are doing. This can be achieved by using high powered standard white light emitters mounted on the diver's helmet, or the like, or on the ROV.

Occasionally these emitters may be handheld or standalone.

When the surrounding water is clear of particles then this works adequately. However, this becomes unworkable when the surrounding environment has a significant number of suspended particles. The use of white light in this environment produces reflection (or back-scatter) of the light from the particles and so causes the eyes or the camera iris to contract thus producing large amounts of glare. Some of the light will still be penetrating the water and lighting the equipment but due to the immediate glare this cannot be seen.

One method to tackle this problem is to use a combination of GPS, acoustic positioning devices and sonar. Such devices, working in parallel, can get an ROV close to the equipment, but they cannot allow for intervention on the equipment due to inaccuracy.

Also, to intervene the ROV or diver must be able to see what they are doing as they may need to work on, for example, a single valve actuation. These devices cannot detect the smaller parts of a larger piece of equipment. The combined cost of these items is also significant.

This background serves to set a scene to allow a skilled reader to better appreciate the following summary and description. Therefore, none of the above discussion should necessarily be taken as an acknowledgement that that discussion is part of the state of the art or is common general knowledge. One or more aspects/embodiments of the invention may or may not address one or more of the background issues.

Summary

According to a first aspect of the invention, there is provided a method of illuminating underwater objects, the method comprising: in an underwater environment, directing ultraviolet light onto the underwater object, such that the ultraviolet light interacts with the object to produce visible light.

"Underwater environment" typically means underwater, for example, subsea. In some embodiments the underwater environment is at least 10 m deep (i.e. measured from the water surface), or at least 50 m deep, and may be at least 100 m deep. For certain embodiments the depth may be more than 250 m, optionally more than 500 m and sometimes more than 1,000 m.

The underwater environment may be within 5 m of the seabed, or within 20 m of the seabed, or 50 m of the seabed.

The underwater object may be partially submerged, or entirely submersed.

Herein ultraviolet and UV are considered to mean the same. UV is a known term of art.

The UV light directed onto the object may be in the range of 100 to 500 nm. The UV light directed onto the object may be in the range 350 to 400 nm.

The underwater object may comprise a surface configured to interact with the UV light (e.g. convert UV light into visible light). This is hereinafter referred to as being "UV reactive". The surface may comprise a coating or paint.. Therefore a UV reactive paint may be applied to the surface of the underwater object for it to function with certain embodiments of the invention. Alternatively, the underwater object may comprise a UV reactive material.

The method may comprise directing ultraviolet light onto one or more underwater objects such that the ultraviolet light interacts with the object(s) to produce different light for receipt by a camera or user (e.g. different visible colours). The different visible light may be distinguishable (e.g. usable to distinguish the particular object being illuminated). In other words, the different visible light may be usable to distinguish between different particular objects being illuminated. For example, the one particular emission of light may be used to suggest a pipeline, while the other may be used to suggest a bolt, nut, or the like. Different light (e.g. different visible light) may be useable to distinguish between particular markings, or labelling, of underwater objects. For example, particular colours can be utilised to create a labelling or marking system on the object for component or interface identification (e.g. distinguishing between cross over values and safety values).

According to a second aspect of the invention there is provided a method of manufacturing an underwater object, the method comprising providing a surface of the underwater object with one or more UV reactive materials.

The surface may be provided by coating the object. The surface may be provided by comprising a UV reactive material with the object (e.g. during manufacture).

The underwater object may comprise at least one of a number of different items of underwater equipment such as wellheads, remotely operated vehicles (ROV5), tubulars, blow-out preventors (BOP5), subsea christmas trees, manifolds, pipelines, protection structures, clump weights, anchors, subsea deployed lifting rigging, flowbases, autonomous underwater vehicles (AUV5), subsea risers, subsea intervention tools, subsea repair clamps, removable or replacement items for any of the above.

The underwater object may be a tool used in the exploration or recovery of hydrocarbons from subsea reservoirs.

According to a third aspect of the invention there is provided a method of using an underwater object, the method comprising deploying an object underwater in an underwater environment, the underwater object comprised with UV reactive material, such as UV reactive paint.

The object may be deployed to a depth of at least 10 m, or at least 20 m or may be deployed to any depth as required, such as more than 50 m or even more.

The method according to any previous aspect of the invention may include: moving, repairing, altering, joining and/or other work with, to, or involving the underwater object; and so one aspect of the invention is a method of working underwater.

According to a fourth aspect of the present invention, there is provided an apparatus for illuminating, the apparatus comprising a UV light source with a housing, the apparatus configured to be usable at a pressure of at least 10 bar, or at least 100 bar.

According to a fifth aspect of the invention, there is provided an apparatus for illuminating for an underwater environment, the apparatus comprising a UV light source with a housing configured to direct ultraviolet light onto underwater objects, such that ultraviolet light interacts with such objects to produce visible light.

The apparatus may be configured to be usable at a pressure of at least 10 bar, or at least 100 bar. The apparatus may be configured to be usable at a pressure of at least bar, or at least 400 bar.

The apparatus may comprise a transparent panel to allow the UV light from the light source to be emitted from the apparatus. Such a transparent panel may be considered to be UV-transmissive. The panel may be transmissive to visible light. The panel may be made from a synthetic fused silica glass. Such glass may be provided with high purity, which might allow for the maximum amount of transmission through the panel.

The transparent panel may be mounted (e.g. sealably mounted) to the housing. The apparatus may comprise a sealing region configured to seal the panel with the housing. The apparatus may comprise an end cap configured so as to mount with the housing such that the transparent panel is urged (e.g. urged in a sealing manner) between the end cap and the sealing region. In such a manner, the light source may be considered to be contained within the housing, end cap and panel.

The end cap may comprise a thread for complementary mating with a thread on the housing. The end cap/housing may comprise one or more interlocking portions, in order to inhibit removal of the end cap and/or to provide for sealing of the transparent panel and the housing.

The end cap and/or housing may comprise aluminium alloy, such as a marine grade (e.g. strong marine grade) aluminium alloy. Such alloys may help optimise a ratio of strength, weight and cost.

The sealing region comprises one or more seals, which may be radial seals. The seal(s) may be deformable seals (e.g. rubber seals). The apparatus may be configured such that, when assembled, the transparent panel compresses the seals of the sealing region in order to seal the housing. The apparatus may be configured such that the end cap is used to urge, or force, the transparent panel to compress the seals. The apparatus may comprise two or more seals, which may be radial seals. The seals may be configured concentrically.

The light source may be configured within, or substantially within the housing. The light source may be configured such that, in use, ultraviolet light exits the apparatus via the transparent panel.

The light source may comprise a substrate (e.g. printed circuit board), upon which there are mounted a one or more ultraviolet emitters (e.g. ultraviolet LEDs). The light source may comprise a plurality of ultraviolet emitters.

The apparatus may be configured such that the major direction of light emitted from each emitter (e.g. each LED) is in substantially the same direction when leaving the apparatus. The apparatus may be configured such that some or all of the emitters provide light in substantially different directions in order to provide an effective larger/broader, or narrower, beam area. For example, some or all of the emitters may be configured to emit light in different directions. The transparent panel may be configured, or lensed, (e.g. concave, or convex), in order to provide an effective larger/broader or smaller/narrower beam area.

The apparatus may comprise one or more mounting arms. The mounting arms may be configured to mount the light source with the apparatus (e.g. with, or within the housing). The mounting arms may be configured to mount the substrate with the apparatus. The mounting arms may comprise one or more absorbing elements, configured to absorb shock and/or vibration forces. The absorbing elements may be elastically deformable elements. The absorbing elements may inhibit, or mitigate the transmission of shocks, vibrations etc. from the housing (or the like) to the light source.

The apparatus may comprise a plurality of mounting arms. Each mounting arm may be spaced from a further mounting arm within the housing. The spacing may be regular or irregular. The mounting arms may be circumferentially spaced from one another.

The apparatus may comprise one or more UV indicators. The UV indicators may be configured so as to allow for the visual identification by an operator of when the apparatus 100 is emitting UV light. The UV indicator(s) may comprise UV reactive material (e.g. UV reactive nylon) such that they emit a visible light in the presence of UV. The UV indicators may be provided within the housing (e.g. within the housing and transparent panel).

The UV indicators may be associated with the light source. The UV indicators may be associated with the one or more mounting arms. The UV indicators may be attached to the one or more mounting arms. The UV indicators may be attached to the one or more mounting arms and serve additionally to restrain the light source with the mounting arms.

The light source may provide a radiant flux in the region of 11 W, or more. The light source may provide a radiant flux of 20 W, or more. The light source may provide a high radiant flux.

The UV light may be used for viewing and overall illumination of underwater objects and equipment.

The apparatus may be configured to be powered externally or internally from stored power. The apparatus may be configured to be mounted to a diver or remotely operated vehicle. The apparatus may be configured to be hand held in use.

According to a sixth aspect of the invention, there is provided a method of illuminating underwater objects, the method comprising: in an underwater environment, directing ultraviolet light onto the underwater object, such that the ultraviolet light interacts with the object to produce observable light.

The light may include visible light.

According to a seventh aspect of the invention, there is provided apparatus for illuminating for an underwater environment, the apparatus comprising a UV light source with a housing configured to direct ultraviolet light onto underwater objects, such that ultraviolet light interacts with such objects to produce observable light.

The light may include visible light.

According to an eighth aspect of the invention, there is provided apparatus for illuminating for an underwater environment, the apparatus comprising a light source with a housing configured to direct light onto underwater objects, such that light interacts with such objects to produce observable light.

The apparatus may comprise one or more mounting arms configure to mount the light source (e.g. mount the light source with the housing). The mounting arms may elastically mount the light source.

According to a ninth aspect of the invention there is provided an underwater vehicle, such as a remotely operated vehicle, comprising the apparatus according to any of the features of the fourth, fifth, seventh or eighth aspects.

According to a tenth aspect of the invention there is provided a diving accessory comprising the apparatus according to any of the features of the fourth, fifth, seventh or eighth aspects.

The underwater vehicle of the ninth aspect or diving accessory of the tenth aspect may comprise additionally one or more visible light sources and/or cameras.

Any feature of any aspect of any invention or embodiment described herein may be combined with any feature of any aspect of any other invention or embodiment described herein mutatis mutandis. For example, the apparatus of the fourth or fifth aspects of the invention may be used in the any of the features of the methods according to the earlier aspects of the invention. Similarly, any features of the fifth aspect may be used with the eighth aspect, etc. The above summary is intended to be merely exemplary and non-limiting.

It will be appreciated that one or more embodiments/aspects may be useful for illuminating underwater objects.

Brief Description of the Figures

A description is now given, by way of example only, with reference to the accompanying drawings, in which:-Figure 1 shows a cross section of apparatus for illuminating; Figure 2 shows example of convex and concave transparent panels of the apparatus of Figure 1; Figure 3 shows various perspective view of the apparatus of Figure 1; Figure 4 shows the apparatus of Figure 1 in use; and Figure 5 shows example of underwater objects having distinguishable markings, or labels.

Description of Specific Embodiments

Figure 1 shows a cross section of apparatus 100 for illuminating, and in particular an illuminating apparatus 100 for underwater objects used in the oil and gas industry, such as wellheads, tubulars, blow-out preventors (BOPs), manifolds, pipelines, protection structures, etc. The apparatus 100 comprises a housing 30, and ultraviolet transparent panel 33. The transparent panel 33 is sealably mounted with the housing 30 using a sealing region 32 and an end cap 31. The end cap 31 is configured so as to mount with the housing 30 such that the transparent panel 31 is urged in a sealing manner between the end cap 31 and the seal region 32. The end cap 31 may comprise a thread for complementary mating with a thread on the housing 30. Alternatively, the end cap/housing may comprise one or more interlocking portions, in order to inhibit removal of the end cap, and to provide for sealing of the transparent panel 32 and the housing 30.

Here, the end cap 31 and the housing 30 comprise aluminium alloy, such as a marine grade (e.g. strong marine grade) aluminium alloy. Such alloys can help optimise a ratio of strength, weight and cost.

In this example, the sealing region 32 comprises two radial seals 32a, 32b, which in this example can be considered concentric. The seals 32a, 32b, are configured to press against the transparent panel 33 and the housing 30 in order to inhibit the ingress of water, in use. Providing two seals 32a, 32b in this manner means that the apparatus 100 may remain sealed, even if one of the seals 32a, 32b fails (e.g. during use).

Here, the transparent panel 33 is made from a synthetic fused silica glass. Such glass can be provided with high purity, which allows for the maximum amount of transmission through the panel.

The apparatus 100 further comprises a light source 34, which in this example is configured so as to be substantially within the housing 30. Of course, in further examples the lights source 34 may be configured within a further portion of the apparatus (e.g. within end cap when mounted with the housing). The light source 34 comprises a substrate 110 (e.g. printed circuit board), upon which there are mounted a plurality of ultraviolet LEDs 120 (Light Emitting Diodes). In some examples, the apparatus 100 is configured such that the direction (e.g. major direction) of light emitted from each LED is in substantially the same direction when leaving the apparatus 100. In alternative examples, the apparatus 100 is configured such that some or all of the LEDs effectively provide light in substantially different directions in order to provide an effective larger beam area of UV light leaving the apparatus 100.

This may be achieved, for example, by configuring some or all of the LEDs to emit light in different directions (e.g. orientating the LEDs on the substrate so that they emit light in different directions). In alternative examples, the transparent panel 33 may be configured, or lensed (e.g. concave, or convex) in order to provide the effective larger or narrower beam area. Figure 2a and 2b shows examples of concave and convex transparent panels 133, 233, respectively for use a transparent panel 33 with the apparatus 100.

The light source 34 is configured such that, in use, ultraviolet light can exit the apparatus 100 via the transparent panel 33. Here, the substrate 110 is mounted with the housing 30 using mounting arms 130. In this example, there are four mounting arms 130, each circumferentially spaced from one another, and each used to mount the substrate 120, or light source 34, to the housing. The use of such mounting arms allows for ease of replacement of the light source 34 (e.g. when charging beam angle, for maintenance, changing frequency of UV emitted, etc.). In this example, each of the mounting arms 130 are mounted to the apparatus 100, which in this case is the housing 30, using absorbing elements 135. Each absorbing element 135 is configured to inhibit or mitigate the transmission of shock and/or vibration from, in this case, the housing, to the light source. The absorbing elements are elastically deformable in order to inhibit/mitigate transmission of shock/vibration.

It has been found that the use such a light source 34, and in particular the UV LEDs, is helpful because it is significantly less susceptible to vibration and/or impact. In addition, the use of LEDs allows for a narrow bandwidth of light to be provided, which means that little or no visible light is emitted. Similarly, the use of such a light source 34 allows for a low power consumption compared to alternative light sources, as well as a longer life span, meaning that less maintenance is required.

The apparatus 100 further comprises UV indicators 35. The UV indicators 35 comprise UV reactive material (e.g. UV reactive nylon) such that they emit a visible light in the presence of UV. The UV indicators 35 are configured so as to allow for the visual identification by an operator of when the apparatus 100 is emitting UV light. A skilled reader will appreciate that otherwise the apparatus 100 would transmit UV light that would appear invisible to the normal eye or camera operating in the visible frequency range. Such a configuration mitigates the need for further circuitry to indicate when the apparatus 100 is emitting UV light.

In this example, UV indicators 35 are provided within the housing 30. Here, the UV indicators 35 are attached to the mounting arms 130 and serve additionally to restrain the light source 34 with the mounting arms 130. Providing the UV indicators 35 with at least a dual purpose allows for a reduction in the cost of manufacture of the apparatus 100.

It will be appreciated that the apparatus 100 can, in some embodiments, be powered internally from stored power, such as a battery. Such an embodiment may be helpful when the apparatus 100 is configured to be hand held in use, mounted to a diver, etc. Additionally or alternatively the apparatus 100 can be configured to be powered from an external source. Such an embodiment may be helpful when mounted or used with a remotely operated vehicle or the like.

Figure 3a shows a cross-section perspective view of the apparatus 100 of Figure 1 in which the cross-section is highlighted. Figure 3b shows a similar cross-section perspective view of the apparatus 100. Figure 3c shows a full perspective view of the apparatus 100.

Figure 4 shows an embodiment of the apparatus 100 in use with a Remotely Operated Vehicle (ROV) 10. Of course, in further examples, a diver, or the like, may use the apparatus 100 (e.g. in a hand held manner, mounted to the diver, etc.).

The ROV 10 comprises thrusters 12, grappling arms 14 and a camera 16. To illuminate the underwater object, in this case a wellhead 50, apparatus 100 comprising ultraviolet (UV) lights 20 are provided, as well as, in this example, visible lights 18. Here, the apparatus 100 is configured to emit UV light between having a wavelength of between 350 to 400 nm.

The underwater object, or wellhead 50, in this example, is coated in UV reactive paint.

In further examples, the object may comprise a UV reactive material.

In use, the visible lights 18 are directed towards the wellhead 50. On the occasion where suspended particles 22 are present, the visible light will be reflected back to the camera 16 causing glare and obscuring the wellhead 50. Thus the UV light 20 of the apparatus 100 is operated and UV light is directed towards the wellhead 50. Whilst some UV light may be reflected back to the camera 16, this will not cause glare or obscure the wellhead 50 because it is not in the visible range. When the UV light reaches the wellhead 50, the UV reactive paint luminesces creating visible light, thus "glowing". This visible light travels back to the camera 16 without glare due to the visible light coming from the opposite direction. The use of luminescence in the visible spectrum allows standard camera equipment to be utilised on ROV's and diver helmets. In addition, divers can view objects being illuminated without the use of additional apparatus.

It has been identified that light having a shorter wavelength (i.e. higher frequency) is not as easily absorbed by the water as light with a lower frequency. Therefore, in some embodiments, the visible light provided has a frequency which would be associated with green, blue, indigo, and/or violet. Maintaining the luminescence within the visual range (e.g. the higher frequency visual range) allows the light to travel further in an underwater environment than if the luminescence was in at a lower frequency (e.g. red, infra-red or near infra-red range). This is due to higher frequency light having a shorter wavelength which is not as easily absorbed by the water. In some examples, the apparatus 100 and/or underwater objects are configured to produce visible light in the blue-violet spectrum (e.g. only in the blue-violet spectrum).

Using the above method/apparatus the operator can see the wellhead 50 (which would otherwise be obscured) and the work may progress thereon. It will be appreciated that the use of UV light removes (or at least mitigates) the problems with visual glare to a human eye, whether directly or through a camera and monitor system. Although the UV light will still be reflected by suspended particles, the resultant reflected light is beyond the human visual spectrum and as such is invisible, or hardly visible.

In addition, the apparatus 100 can also be used in environments where there are little or no entrained particles in the water. The object will still be illuminated in the same manner and indeed potentially has more UV light reaching it. Similarly, in some embodiments, the apparatus 100 can be used without the additional use of a visible light source.

In some examples, the method includes providing particular underwater objects such that they emit an identifiable frequency of light (e.g. within the visible spectrum). For example, in some embodiments, bolts or nuts of a wellhead 50, or the like, can be coated in a particular coating allow for a particular colour of light to be emitted upon interaction with ultraviolet light, while other objects (e.g. pipes, etc.) may be configured to emit an alternative colour of light. In such a manner, an operator would be easily able to distinguish between particular features of the underwater object. Similarly, different colours can be utilised to create identifiable markings or labels on the underwater object. Figure 5 shows a simplified example of an underwater object 200 on which a first marker 210 is configured to emit green frequencies, while a second marker 220 is configured to emit blue frequencies. In this case, the first marker 200 indicates a first value (e.g. cross over valve), while the second marker 210 indicates a second value (e.g. safety valve). In such a manner, a user or operator is able to quickly determine the objects being illuminated, and intervene accordingly.

In some embodiments, the use of identifiable or distinguishing coatings, or the like, may be used in addition to visible light in order to assist an ROV operator, diver, etc. It will be appreciated that while the above apparatus 100 has been described specifically for use with a UV light source 34, a skilled reader will appreciate that described features of the apparatus 100 may find particular use with an alternative light sources (e.g. a visible light source). For example, in some cases, the apparatus 100 may be used without the UV light source, but may including some further features herein described (e.g. the seals 32a, 32b, or the mounting arms 130, etc.). A skilled reader will readily be able to implement those further embodiments accordingly.

Improvements and modifications may be made without departing from the scope of the invention.

Claims

CLAIMS1. A method of illuminating underwater objects, the method comprising: in an underwater environment, directing ultraviolet light onto the underwater object, such that the ultraviolet light interacts with the object to produce visible light.
2. A method as claimed in claim 1, wherein the UV directed onto the object is in the range of 350 -400 nm.
3. A method as claimed in either preceding claim, wherein the object comprises a UV reactive surface.
4. A method as claimed in any preceding claim, wherein the underwater environment is at least 20 m deep, or at least 50 m deep.
5. A method as claimed in any preceding claim, wherein the ultraviolet light is directed from a light source held by or connected to a diver.
6. A method as claimed in any of claims 1 to 4, wherein the ultraviolet light is directed from a light source mounted to a Remotely Operated Vehicle (ROV).
7. A method as claimed in any preceding claim, wherein the underwater environment is within 20 m of the seabed.
8. A method according to any preceding claim comprising directing ultraviolet light onto the underwater object, such that the ultraviolet light interacts with the object so as to produce one or more distinguishable visible lights, each distinguishable visible light associated with different features of the object.
9. A method according to claim 8, wherein each distinguishable light provides light of a different spectrum or frequency, for example, a different visible colour.
10. A method as claimed in any preceding claim, wherein the underwater object is a tool used in the exploration or recovery of hydrocarbons from subsea reservoirs.
11. A method as claimed in any one of claims 1 to 9, wherein the underwater object comprises at least one from the list consisting of wellheads, remotely operated vehicles (ROV5), tubulars, blow-our preventors (BOPs), subsea christmas trees, manifolds, pipelines, protection structures, clump weights, anchors, subsea deployed lifting rigging, flowbases, autonomous underwater vehicles (AUV5), subsea risers, subsea intervention tools, subsea repair clamps, and removable and replacement items for said objects.
12. A method of manufacturing an underwater object, the method comprising coating a surface of the underwater object with a UV reactive paint, or manufacturing an underwater object comprising a UV reactive material.
13. A method as claimed in claim 12, wherein the underwater object comprises at least one from the list consisting of wellheads, remotely operated vehicles (ROVs), tubulars, blow-our preventors (BOP5), subsea christmas trees, manifolds, pipelines, protection structures, clump weights, anchors, subsea deployed lifting rigging, flowbases, autonomous underwater vehicles (AUV5), subsea risers, subsea intervention tools, subsea repair clamps, and removable and replacement items for said objects.
14. A method of using an underwater object, the method comprising deploying an underwater object to a underwater environment, wherein the underwater object is configured with UV reactive material so as to emit visible light upon interaction with UV light.
15. A method as claimed in claim 14, wherein the object is deployed to a depth of atleastlO m, or at least 50 m.
16. Apparatus for illuminating, the apparatus comprising a UV light source with a housing configured to direct ultraviolet light onto underwater objects, such that ultraviolet light interacts with such objects to produce visible light.
17. The apparatus according to claim 16, wherein the apparatus is configured to be usable at a pressure of at least 10 bar, or at least 100 bar, or at least 200 bar, or at least 400 bar.
18. The apparatus according to claim 16 or 17, comprising a transparent panel to allow the UV light from the light source to be emitted from the apparatus, for example, a transparent panel comprising synthetic fused silica glass.
19. The apparatus according to claim 18, wherein the transparent panel is configured in order to provide an effective larger or narrower beam area of UV light from the light source.
20. The apparatus of claim 18 or 19 wherein the transparent panel is sealably mounted to the housing at at least one or more sealing regions.
21. The apparatus according to claim 20, wherein the apparatus comprises an end cap configured to mount with the housing such that the transparent panel is urged in a sealing manner between the end cap and the sealing region.22. The apparatus according to claim 20 or 21, wherein the sealing region comprises two or more concentric radial seals to allow for sealing of the housing.
22. The apparatus according to any of the claims 16 to 21 wherein the light source comprises a substrate, upon which there are mounted one or more ultraviolet LEDs.
23. The apparatus according to any of the claims 16 to 21 wherein the apparatus comprises one or more mounting arms, each mounting arm configured to mount the light source within the housing.
24. The apparatus according to claim 23, wherein one or more mounting arms comprises an absorbing element, configured to inhibit or mitigate the transmission of shock and/or vibration to the light source.
25. The apparatus according to any of the claims 16 to 24, wherein the apparatus comprises one or more UV indicators, the UV indicator(s) configured so as to allow for visual identification by an user of when the apparatus is emitting UV light.
26. The apparatus according to claim 25, wherein the UV indicator(s) comprise UV reactive material, such as UV reactive nylon, so as to emit a visible light in the presence of UV.
27. The apparatus according to claim 26 wherein the UV indicators are provided within the housing or apparatus.
28. The apparatus according to any of the claims 25 to 27, when dependent upon claim 23, wherein the UV indicators are associated with the one or more mounting arms.
29. The apparatus according to claim 28, wherein the UV indicators are attached to the one mounting arms and serve additionally to restrain the light source with the mounting arms.
30. The apparatus according to any of the claims 16 to 29 wherein the apparatus is configured to be mounted to a diver or remotely operated vehicle, or is configured to be hand held in use.
31. One or more underwater object for use in the oil and gas industry, configured to emit one visible light upon interaction with UV light provided from an apparatus according to any of the claims 16 to 30.
32. Object(s) according to claim 31, configured to emit different particular frequencies of visible light upon interaction with UV light in order to allow for distinguishing different features of the object(s).
33. Underwater vehicle, such as a remotely operated vehicle, comprising the apparatus according to any of the claims 16 to 30.
34. A diving accessory comprising the apparatus according to any of the claims 16 to 30, wherein the accessory is configured with use with a diver.
35. Methods substantially as described with reference to the Figures.
36. Apparatus substantially as described with reference to the Figures.