diff --git a/layers/boundary/boundary.sql b/layers/boundary/boundary.sql
index 0c41a13..d45bfd5 100644
--- a/layers/boundary/boundary.sql
+++ b/layers/boundary/boundary.sql
@@ -7,102 +7,121 @@ CREATE OR REPLACE FUNCTION edit_name(name VARCHAR) RETURNS TEXT AS $$
 $$ LANGUAGE SQL IMMUTABLE;
 
 
-
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen1
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen1 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen1 AS
     SELECT ST_Simplify(geometry, 10) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen1 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen1;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen2
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen2 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen2 AS
     SELECT ST_Simplify(geometry, 20) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen2 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen2;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen3
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen3 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen3 AS
     SELECT ST_Simplify(geometry, 40) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen3 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen3;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen4
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen4 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen4 AS
     SELECT ST_Simplify(geometry, 80) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen4 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen4;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen5
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen5 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen5 AS
     SELECT ST_Simplify(geometry, 160) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen5 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen5;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen6
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen6 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen6 AS
     SELECT ST_Simplify(geometry, 300) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen6 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen6;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen7
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen7 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen7 AS
     SELECT ST_Simplify(geometry, 600) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen7 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen7;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen8
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen8 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen8 AS
     SELECT ST_Simplify(geometry, 1200) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen8 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen8;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen9
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen9 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen9 AS
     SELECT ST_Simplify(geometry, 2400) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen9 USING gist (geometry);
 ANALYZE osm_border_disp_linestring_gen9;
 
+-- etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen10
 DROP TABLE IF EXISTS osm_border_disp_linestring_gen10 CASCADE;
 CREATE TABLE osm_border_disp_linestring_gen10 AS
     SELECT ST_Simplify(geometry, 4800) AS geometry,
         osm_id, admin_level,
-        concat_ws('_', edit_name(name), claimed_by) AS disputed_view
+        concat_ws('_', edit_name(name), claimed_by) AS disputed_view,
+        maritime
     FROM osm_border_disp_linestring
     WHERE admin_level = '2';
 CREATE INDEX ON osm_border_disp_linestring_gen10 USING gist (geometry);
@@ -194,7 +213,7 @@ CREATE OR REPLACE VIEW boundary_z5 AS (
     FROM osm_border_linestring_gen9
     WHERE admin_level <= 4
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen9
 );
 
@@ -205,7 +224,7 @@ CREATE OR REPLACE VIEW boundary_z6 AS (
     FROM osm_border_linestring_gen8
     WHERE admin_level <= 4
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen8
 );
 
@@ -216,7 +235,7 @@ CREATE OR REPLACE VIEW boundary_z7 AS (
     FROM osm_border_linestring_gen7
     WHERE admin_level <= 4
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen7
 );
 
@@ -227,7 +246,7 @@ CREATE OR REPLACE VIEW boundary_z8 AS (
     FROM osm_border_linestring_gen6
     WHERE admin_level <= 4
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen6
 );
 
@@ -238,7 +257,7 @@ CREATE OR REPLACE VIEW boundary_z9 AS (
     FROM osm_border_linestring_gen5
     WHERE admin_level <= 6
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen5
 );
 
@@ -249,7 +268,7 @@ CREATE OR REPLACE VIEW boundary_z10 AS (
     FROM osm_border_linestring_gen4
     WHERE admin_level <= 6
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen4
 );
 
@@ -260,7 +279,7 @@ CREATE OR REPLACE VIEW boundary_z11 AS (
     FROM osm_border_linestring_gen3
     WHERE admin_level <= 8
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen3
 );
 
@@ -270,7 +289,7 @@ CREATE OR REPLACE VIEW boundary_z12 AS (
     SELECT geometry, admin_level, disputed, NULL AS disputed_view, maritime
     FROM osm_border_linestring_gen2
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen2
 );
 
@@ -280,7 +299,7 @@ CREATE OR REPLACE VIEW boundary_z13 AS (
     SELECT geometry, admin_level, disputed, NULL AS disputed_view, maritime
     FROM osm_border_linestring_gen1
     UNION ALL
-    SELECT geometry, admin_level::int, true AS disputed, disputed_view, false AS maritime
+    SELECT geometry, admin_level, true AS disputed, disputed_view, maritime
     FROM osm_border_disp_linestring_gen1
 );
 
diff --git a/layers/boundary/etl_diagram.png b/layers/boundary/etl_diagram.png
index 53f4eef..1011a7f 100644
Binary files a/layers/boundary/etl_diagram.png and b/layers/boundary/etl_diagram.png differ
diff --git a/layers/boundary/mapping.yaml b/layers/boundary/mapping.yaml
index 3cfc10e..f25a9ec 100644
--- a/layers/boundary/mapping.yaml
+++ b/layers/boundary/mapping.yaml
@@ -1,5 +1,5 @@
 generalized_tables:
-  # etldoc: imposm3 -> osm_border_disp_linestring
+  # etldoc: osm_border_disp_relation -> osm_border_disp_linestring
   border_disp_linestring:
     source: border_disp_relation
     sql_filter: ST_GeometryType(geometry) = 'ST_LineString'
@@ -9,8 +9,11 @@ tables:
   border_disp_relation:
     type: relation_member
     fields:
+    - name: relation_id
+      type: id
     - name: osm_id
       type: id
+      from_member: true
     - name: geometry
       type: geometry
     - key: name
@@ -21,13 +24,17 @@ tables:
       type: string
     - key: admin_level
       name: admin_level
-      type: string
+      type: integer
     - key: claimed_by
       name: claimed_by
       type: string
     - key: disputed_by
       name: disputed_by
       type: string
+    - key: maritime
+      name: maritime
+      type: bool
+      from_member: true
     mapping:
       type: [boundary]
     filters:
diff --git a/layers/boundary/mapping_diagram.png b/layers/boundary/mapping_diagram.png
new file mode 100644
index 0000000..1eb7fb2
Binary files /dev/null and b/layers/boundary/mapping_diagram.png differ