Mapping Seabed

Additional seabed mapping requirements & OSGB36 coordinates

Regulation 8 of the Land Register Rules etc. (Scotland) Regulations 2014, sets out that there are two additional requirements that must be met when an application is submitted to register a seabed plot that falls wholly within the sea or tidal waters (including sea lochs, estuaries, tidal rivers and bays):

• the deed must contain a description of the plot of land based on the British national coordinate system: OSGB 1936 - British National Grid (ESPG:27700), also known as OSGB36 for short; and
• the deed must contain a location plan identifying the position of the seabed plot in relation to the coast of Scotland.

All OS mapping in Great Britain uses the OSGB36 National Grid coordinate reference system, and it is a widely accepted industry standard. The coordinate system is linked to a country-wide triangulation network that includes thousands of known points including the traditional white trig pillars that can be found on many hills. 

Full details on what is required in an application to describe a seabed plot can be read in guidance page Acceptable Seabed Plot Descriptions.

The use of coordinates is a requirement even where:

• the seabed plot is located in close proximity to, or adjoining, the coast, or
• the seabed plot adjoins another defined feature on the OS Map, such as a pier or jetty, or
• the plot includes, or is wholly comprised of, a defined feature on the OS Map, such as a pier or jetty, but the plot lies wholly below the Mean Low Water Springs (MLWS).

Since the use of coordinate data will effectively determine the location and extent of the seabed plot for mapping purposes, the deed plan only needs to identify the location of the plot relative to the coastline of Scotland. For this reason, it is acceptable for the deed or location plan to be at a smaller scale than that specified in the deed plan criteria, provided the plot is described sufficiently by coordinates.

Plans and legal officers - responsibilities for coordinates

It is a requirement that the OSGB36 coordinates are disclosed in the property section of the seabed title sheet, and a Schedule of Coordinates has been added to the LRS for this purpose.

• It is the responsibility of the legal settler to add the schedule of coordinates to the title sheet.
  
  
• The plans settler should add appropriate notes to the title workdesk to inform the legal settler that the plot has been mapped using OSGB36 coordinate information, and any other necessary explanation.
• Where a list of coordinates has been included as part of the digital data provided by the applicant, the plans settler should transfer this data into an excel spreadsheet (see section below on for use by the legal settler where possible. 
• The deed inducing registration of the seabed plot may include coordinates for the extent of the plot and for additional or ancillary rights/burdens. Only the coordinates for the extent of the plot are required in the property section, and therefore the plans officer should extract these from the deed and provide only the relevant coordinates for the legal settler.

Cadastral unit split - separating land and seabed

It is normal practice for the Keeper to divide or split a cadastral unit where the plot being registered comprises both seabed and land or foreshore, i.e. where parts of the plot are located above and below the Mean Low Water Springs (MLWS). It is unlikely to be clear at intake that a cadastral unit split may be appropriate, therefore the decision to split a cadastral unit will be considered at plans settle stage. The plans officer should initially check the extent of the plot against the OS map and establish if:

• the whole plot lies below the MLWS - the whole plot should be registered in the county of SEA;
• the whole plot lies above the MLWS (land or foreshore) - the whole plot should be registered in the appropriate landward registration county; or
• the plot lies partly above and partly below the MLWS (land or foreshore, and seabed) - consideration should be given to splitting the application into separate cadastral units and title sheets in the county of SEA and the appropriate landwards registration county.

Where the plot to be registered comprises areas above and below the MLWS, and the plans officer considers that a cadastral unit split may be necessary, they should refer the application to a senior caseworker who will make the decision on whether splitting the cadastral unit is appropriate or not. Alternatively, if the plot does not comprise areas above and below the MLWS but has been taken on against the wrong county (for example, the plot is actually foreshore rather than seabed but has been taken on in the county of SEA), the authorisation of a senior caseworker will be needed so the application can be cancelled and recreated in the correct county.  

Splitting the title will not be appropriate in all circumstances however:

• Where the plot straddles both seabed and land or foreshore, and these areas are occupied by a permanent feature, such as a jetty or pier, a cadastral unit split is not appropriate.
• Where the plot comprises one or more areas of seabed and land or foreshore, which on their own are very small or fragmented, it may not be practical or expedient to split the areas into separate cadastral units.

If the decision of the senior caseworker is that the application is to be split, the plans officer will then need to arrange for a second application to be created. This can be done by completing the L32 Intake Create Instructions form that can be found in the LRS and passing to an Intake officer. When completing the L32, remember that the application types of both applications should be the same; for example, if the original application is an FR, then the additional application will normally be an FR too. The registration date of the additional application will be the same as the registration date of the original application. And no fee is charged to the applicant for the additional application as the splitting of the title is an admin process decided upon by the Keeper.

When the applications are returned from Intake, the plans officer should ensure that the two applications are processed together, and that movement notes are added to the LRS, for example, "Travelling with 24SEAxxxx". When mapping the two applications, the cadastral units will be split at the MLWS, resulting in the seabed part being registered in the county of SEA, and the land and/or foreshore part being registered in the appropriate land county. Each part will have a separate cadastral unit and title sheet, and the property section descriptions should reflect the part of the plot included in that particular title.

Key points for plans settlers

The plans registration process for registering seabed is broadly similar to that for the registration of other areas of land. In addition to the reference or references required for the extent of the plot, there may also be plans references required for rights or burdens affecting the cadastral unit. Consideration of the size and shape of the polygons should be given when choosing the most appropriate plans reference to use in the Plan Creator. However, given the additional requirements set out above relating to the provision of coordinate data, there are some significant differences in how seabed applications must be treated and processed. The key differences are set out below:

Mapping the seabed plot - using digital data

In addition to providing a list of coordinates to identify the extent of a seabed plot, the applicant may also chose to provide digital data for the extent of the plot. Provision of digital data is not, however, a legal requirement upon the applicant although it can be very useful to the Keeper. It is normally provided when the seabed application comprises large items like offshore wind farms or cable corridors, or for particularly complex shapes. If the digital data is not provided with the application, the plans officer may still consider requesting the digital data, particularly where the extent of the seabed plot comprises a large number of coordinates/complex shape.

It is likely that the majority of deeds relating to, or comprising, seabed will be granted by Crown Estate Scotland (CES).  CES have confirmed that the coordinate data can be made available in a shapefile format for any seabed deeds they grant. Therefore, if digital data has not been provided for an application being granted by CES and the plans officer feels it would be useful when mapping the seabed plot, please contact them to request the digital data.

The guidance on Digital Map Data & Digital Deed Plans should be followed when considering to use digital data.

Mapping the seabed plot - OSGB36 coordinates

The deed being registered must contain a description of any wholly seabed plot based on OSGB36 coordinates. Full details of when coordinates are required in a particular type of application can be found in The Description of Seabed Plot Must Be Acceptable . The coordinates can be included in the descriptive text of the deed, in a table in the deed, or annotated on the deed/location plan:

Example 1 - coordinates shown on deed plan
In this application, the subjects are described solely by reference to the extent shown on the deed plan, however the coordinates are clearly annotated on the deed plan so the description is acceptable.  This method of including the coordinates in the application tends only to be used when the actual number of coordinates is small.

Example 2 - coordinates given in a table or schedule
In this application, the subjects (The Site) are described by reference to the extent shown on the deed plan and also the coordinates in the Schedule, so the description is acceptable.  This particular Schedule also contains the coordinates for a burden or right affecting the title (The Corridor) - these shouldn't be included in the Schedule of Coordinates in the title sheet. See Info note below.

The coordinates supplied in the application may be used by the plans settler to help map the seabed plot on the cadastral map. In the Plan Creator, the OS coordinate information of the current position of the cursor is displayed at the bottom of the Plan Creator window and can be used to accurately position each vector point. In general, there is no requirement for the plans officer to identify the coordinates proved in the deed by labelling the boundary points on the cadastral map, see guidance on labelling, below, for more detail.

Whilst it is the legal settler's responsibility to add a Schedule of Coordinates to the title sheet, the plans settler should add a title note to inform the legal settler that the plot has been mapped using OSGB36 coordinate information:

"Cadastral unit SEAxxx has been mapped using the OSGB36 coordinates information in [deed x / schedule y to deed x / plan z to deed x]."

Where a list of coordinates has been included as part of the digital data (see below) provided by the applicant, the plans settler should transfer this data into an excel spreadsheet for use by the legal settler where possible.

Labelling the coordinates that make up the boundaries of the plot

In general, there is no requirement for the plans officer to identify the coordinates proved in the deed by labelling the boundary points on the cadastral map. In the vast majority of SEA titles, the plotting of the polygon(s) on the cadastral map and the the inclusion of the Schedule of Coordinates in the title sheet is sufficient, and meets the Keeper's obligations.

Whilst it would be simple to label the four corners of a square plot as only four coordinates will have been provided, it would not be practical to label larger, more complex plots with tens or hundreds of coordinates provided. As the legislation does not require the labelling of coordinates, a consistent approach should be taken and boundary points should not be labelled, except:

• when coordinates are not provided for sections of boundaries (see sections below on MLWS & MHWS)
• when polygons are particularly complex and are derived from both lists of coordinates and parts of circular references (see sections below on combined plots)
• when polygons are particularly large and complex and the HEO plans officer believes labelling some or all coordinates would aid interpretation of the plot - such applications should be discussed with a SEO plans as while labelling in such scenarios may be appropriate in a specific case, it is a deviation from the normal rules.

Mapping the seabed plot - OSGB36 coordinates for rights and burdens

Where the deed or application also provides coordinates for other plans references (rights or burdens). These rights or burdens may relate to areas (for example, dredging zones), lines (for example, access routes or cable routes) or circular/point features (for example, marker buoys or mooring points).  These coordinates may be used by the plans settler to map the areas/lines/points however they should not be provided to the legal settler as the coordinates for rights or burdens are not to be added to the Schedule of Coordinates. The Schedule of Coordinates in the title sheet is only to include the coordinates defining the boundaries of the plot(s).

• If the coordinates are only included in the deed, advise the legal settler with an LRS note which coordinates are to be used in the Schedule.
• If the coordinates are provided as a list in the digital data, extract only the ones relevant to the plot of land and transfer those to the excel spreadsheet being prepared for the legal settler.

Mapping the seabed plot - reference to the MLWS

Where the seabed plot is bounded by the foreshore it is acceptable to describe that boundary by reference to the foreshore or the MLWS (mean low water, ordinary spring tides) as an alternative to providing coordinates for that particular boundary.  The MLWS is a defined feature on the Ordnance Map, and it is acceptable for identification purposes to tie the boundary to this feature in the description in the deed.  For example the deed could narrate: "…the boundary between the points marked A and B on the plan follows the MLWS…" In this example points A and B mark the points where the sea boundaries intersect with the MLWS.  This method is particularly useful where the boundary in question follows a sizeable stretch of undulating coastline. Coordinate information must be provided for the other seaward boundaries. 

Example 1 - MLWS referred to in deed	Example 2 - MLWS not referred to in deed
In this application, the subjects are described by reference to the extent shown on the deed plan and also the coordinates in the Schedule, so the description is acceptable.  We can see from looking at the deed plan that the plot is bounded by the MLWS, and that information is also included in the coordinate schedule in the deed (extract of schedule included above). Only the coordinates for the two end points of the MLWS section of boundary are included.  The MLWS part of the boundary should therefore be labelled, and reference to it should be made in the note to the Legal settler. A MLWS note will then be added to the title sheet as well as the Schedule of Coordinates.	In this application, the subjects are described by reference to the extent shown on the deed plan and also the coordinates in the Schedule, so the description is acceptable.  Although we can see from looking at the deed plan that the plot is bounded by the MLWS, that information is not supplied in the description or the coordinate schedule - instead the coordinates for the coastal section are provided in a lengthy list. In examples such as this, there would be no requirement to label the MLWS part of the boundary, and no reference to it should be made in the note to the Legal settler. No MLWS note will be added to the title sheet, just the Schedule of Coordinates.

The plans settler should therefore use a combination of the coordinates (see guidance, above) and the definition of the MLWS to plot the extent of the seabed plot on the cadastral map. Letter references (for example, A & B in blue) should be used to mark the ends of the boundary defined as the MLWS, and can be added using the label functionality in the Plan Creator. These letters will be used by the legal settler in the note accompanying the Schedule of Coordinates. The plans settler must add a title note to inform the legal settler that the plot has been mapped using a combination of the OSGB36 coordinate information & the MLWS:

"Cadastral unit SEAxxx has been mapped using a combination of the coordinate information in [deed x / schedule y to deed x / plan to deed x] and the MLWS [between points A & B in blue on the cadastral map]. [Coordinate data/No coordinate data] has been provided for the boundary following the MLWS."

Mapping the seabed plot - reference to the MHWS

The ground between the MLWS and MHWS, known as foreshore, forms part of the relevant landward registration county rather than part of the registration county of SEA. Therefore, when a seabed application makes reference to a boundary following the MHWS, this is normally an indication to us that the application includes foreshore and we need to consider whether the application should be split (see guidance above on Cadastral unit split - separating land and seabed).

However, there are also parts of the Scottish coastline with sea cliffs. In these areas, the OS map often shows a single line feature to represent the MLWS & the MHWS as the cliff is effectively vertical. For example, see the section of coastline between points A & B on this OS map extract.

As explained above in Mapping the seabed plot - reference to the MLWS, it is acceptable to describe a MLWS boundary verbally rather than provide the coordinates for that part of the plot boundary. This same rule applies when the MLWS & MHWS are stacked vertically and shown with a single mapped feature on the OS map. The deed description or schedule may refer to MLWS, MLHS or a combination of both in this type of scenario, but they effectively all refer to the same line feature on the map. For example:

In addition to labelling the parts of the boundary following the MLWS, the plans settler should map the plot using letter references to mark the ends of that part of the boundary comprising vertically stacked MLWS/MHWS using the label functionality in the Plan Creator. 

Following the guidance, above, the plans settler should therefore use a combination of the coordinates (see guidance, above) and the definition of the MLWS and MLWS/MHWS to plot the extent of the seabed plot on the cadastral map. Letter references (for example, A & B in blue) should be used to mark the ends of the boundary defined as the MLWS, and defined as MLWS/MHWS, and can be added using the label functionality in the Plan Creator. These letters will be used by the legal settler in the note accompanying the Schedule of Coordinates. The plans settler must add an expanded title note to inform the legal settler that the plot has been mapped using a combination of the OSGB36 coordinate information, the MLWS, and the MLWS/MHWS, for example:

"Cadastral unit SEAxxx has been mapped using a combination of the coordinate information in [deed x / schedule y to deed x / plan to deed x] and the MLWS between points B & C and D & E in blue on the cadastral map. No coordinate data has been provided for the boundary following the line of MLWS. In respect of the boundary labelled A & B in blue on the cadastral map, the table of coordinates in [deed x / schedule y to deed x / plan to deed x]  says “between points 9 and 1 follows MHWS”.  The MHWS and MLWS converge along this line so the MLWS and MHWS are coextensive and the boundary between points A & B follows the MLWS/MHWS. No coordinate data has been provided for the boundary following the line of MLWS/MHWS.

Mapping the seabed plot - circular plots

Sometimes, the seabed plot is a circular feature such as a mooring point, an anchor point, or the site of a turbine. The description of the plot will be either: (1) a series of coordinates to define the edge of the circle, or (2) a single coordinate described as being the central point, together with a diameter or radius measurement.

Example - centre point coordinates with diameter measurement
In this application, the Subjects (The Buoys) are described by reference to points shown on the deed plan and the coordinates of the centre points are clearly shown in a table on the plan. The text of the deed provides the distance measurement (in this case, the diameter) of each circular area centred on these points. This style of description is acceptable.

The full extent of the circular feature should be plotted on the cadastral map:

• Remember to pay close attention to whether the measurement given from the centre point is the radius or the diameter.
• If the diameter is given, the measurement should be halved to obtain the radius.
• The Distance Offset tool in the Plan Creator can be used when plotting along a circle based on a centre point with a radius measurement.

If the circular plot or plots are described by a full list of coordinates defining the edge of the circle or circles, the plans settler should add a title note to inform the legal settler that the plot has been mapped using OSGB36 coordinate information. The legal settler will use this information to create a Schedule of Coordinates in the title sheet:

"Cadastral unit SEAxxx has been mapped using the OSGB36 coordinates information in [deed x / schedule y to deed x / plan z to deed x]."

If the circular plot is described by a central coordinate with a diameter or radius measurement, the legal settler will need to create a Schedule of Coordinates to the title sheet and add a note after giving the diameter or radius measurement. The plans settler should add a title note informing the legal settler that the plot or plots on the cadastral map have been mapped from this information:

"Cadastral unit SEAxxx has been mapped using the OSGB36 coordinates and radius/diameter information in [deed x / schedule y to deed x / plan to deed x].";

If the circular plots are different dimensions, a more detailed LRS note will be needed as the legal settler will have to expand the note in the title sheet to include this information:

"Cadastral unit SEAxxx has been mapped using the OSGB36 coordinates and radius/diameter information in [deed x / schedule y to deed x / plan to deed x]. The Entries for centre points 1 and 2 in the coordinate list/on the deed plan have a radius measurement of 5m, the Entries for centre points 3, 4 & 5 in the coordinate list/on the deed plan have a radius measurement of 10m."

Mapping the seabed plot - titles including a combination of areas and circular plots

When a deed includes both plots of seabed with coordinates, and circular plots with centre point coordinates, the resulting title will be mapped using a combination of the methods for:

• a "normal" seabed plot (see Mapping the seabed plot - OSGB36 coordinates guidance, above), and 
• circular seabed plots (see Mapping the seabed plot - circular plots guidance, above).
• In addition, depending on the particular title, you may also have to take into account MLWS references, too.

In these instances where we have different styles of coordinate use in a single title, it will often be helpful to provide separate colour references for the part(s) that comprise the plots with coordinates, and for the part(s) comprising circles with centre points as this assists legal with preparing the necessary note for the Property section of the title sheet. There is no set rule for which colour or style of reference is used (other than applying normal mapping conventions), instead the important thing is for the relatively complex situation to be made clear in the title note provided to the legal settler. For example, 

"Cadastral unit SEAxxx has been mapped using a combination of the OSGB36 coordinates and radius/diameter information in [deed x / schedule y to deed x / plan to deed x]. Entries 1 to 17 in the coordinate list/on the deed plan are the coordinates for that part of the sitt tinted pink on the cadastral map. Entries 18, 19 & 20  in the coordinate list/on the deed plan are the centre points for the parts tinted blue on the cadastral map and have a radius measurement of 10m."

Mapping the seabed plot - holes or island sites

There will be applications where there are holes or island sites within the extent of the seabed plots. Particular care should be paid to the deed plans to ensure any islets, pier footings, etc that are not included within the plot are omitted from the cadastral unit.

Example - sea bed plots with holes or island sites
In this application, the subjects are described by reference to areas shown on the deed plan and the coordinates in a Schedule.  This style of description is therefore acceptable. It should be noted that each of the areas being registered is shown on the deed plan with a hole or excepted area roughly in the centre of each pink tint. When plotting the extent of the cadastral unit on the cadastral map, the plan settler should ensure that these holes or excepted areas are not included.

The Cookie Cutter tool in the Plan Creator should be used when plotting areas such as these to remove the hole/island/excepted area from the extent of the cadastral unit. When the plots and island sites are small, generally speaking a tint reference will be clearer than using an edge reference.

Mapping the seabed plot - territorial sea limit

The Territorial Sea Act 1987 provides that the territorial limit for Scottish waters is 12 nautical miles. Prior to the 1987 Act, the territorial sea limit was 3 nautical miles. See The Description of Seabed Plot Must Be Acceptable for details of when to accept or reject a description referring to the territorial limit.

If any part of a seabed plot defined in an application lies beyond the 12 nautical mile territorial sea limit, the cadastral unit will be restricted to exclude the part beyond the 12 nautical mile limit. Any application that appears to include seabed lying beyond the 12 nautical mile territorial sea limit should be referred to a plans senior caseworker for consideration.

Mapping the seabed plot - leases

As with any other plot of land, it is possible to register a lease or sub-lease that consists of or includes seabed. If the ownership of the plot is not already registered, registration of a lease or sub-lease triggers Automatic Plot Registration (APR) in the normal manner. See the Further Guidance section Mapping of Leases for details of the various aspects of mapping the landlord's and tenant's titles.

There will be cases where a lease is submitted for registration that straddles both land and seabed. If the ownership of the plot or plots is already registered, the lease title sheet will refer to the cadastral unit(s) for the plot(s). If APR is triggered, and it is decided that the ownership is to be split into a cadastral unit for the land and a cadastral unit for the seabed, the lease title sheet will refer to both cadastral units even though one is SEAxxx and the other is (for example) ANGxxx. See How to Map a Lease or Sub-lease Affecting More Than One Landlord's Title for guidance on the style of the lease title sheet.

See the section above relating to Digital Data - the majority of leases/sub-leases of seabed plots have Crown Estate Scotland as one of the parties so it is likely that digital data is available to assist with mapping the plots being leased.

Some leases of seabed also include ancillary rights (such as rights of access, rights of mooring at mooring points, etc), and as with leases of inland plots of land these ancillary rights are not mapped on the cadastral map when registering a lease (or sub-lease). Instead the whole deed will be incorporated into the title sheet by reference to the archive record and therefore the information relating to the ancillary rights is not lost.

Mapping the seabed plot - salmon fishings and rights to shellfish

As salmon fishing rights or the rights to gather naturally occurring oysters and mussels are separate legal tenements, it is also acceptable to register ownership, a lease or a sub-lease of these rights in the county of SEA. The basic SEA rules regarding coordinates, etc apply to any legal tenement that is situated below the MLWS.

For cases relating to salmon fishings in the county of SEA, the plans HEO should combine the guidance on this page along with the guidance on mapping of salmon fishings. In addition, the Further Guidance section Mapping of Leases will be of help if a lease or sub-lease is involved.

For cases relating to the right to gather certain shellfish (naturally occurring oysters and mussels), please refer to a plans senior caseworker in the first instance, who may also wish to discuss the application with Policy. Once more live examples of this type of casework has been received by the Keeper, additional guidance will be added to the manual.