diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9a3ccfd..9e8e274 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,24 @@
 # CHANGELOG
 
 
+## v5.3.0-rc.1 (2024-10-15)
+
+### Features
+
+* feat(io): add io & mappings for ImplicitStructuralModel & ImplicitCrossSection
+closes #94 ([`1c0cfa5`](https://github.com/Geode-solutions/OpenGeodeWeb-Back/commit/1c0cfa5051c0931fdbace2ec0c58782d9b5f3c10))
+
+### Unknown
+
+* Merge pull request #97 from Geode-solutions/feat/implicit_cross_section_and_structural_model
+
+feat(io): add io & mappings for ImplicitStructuralModel & ImplicitCro… ([`25723a4`](https://github.com/Geode-solutions/OpenGeodeWeb-Back/commit/25723a4f4c1fe04a7473dfc0b6e9132eab30a8e8))
+
+* save_viewable_implicit_structural_model ([`0cceb4a`](https://github.com/Geode-solutions/OpenGeodeWeb-Back/commit/0cceb4afd051b8c3a756571bc0578d1a27431c6c))
+
+*  ([`000b1f1`](https://github.com/Geode-solutions/OpenGeodeWeb-Back/commit/000b1f1d1c57b4ca77458addfa5919d55101cdc9))
+
+
 ## v5.2.0 (2024-10-14)
 
 ### Unknown
diff --git a/pyproject.toml b/pyproject.toml
index 51bc9ff..6cabb54 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "OpenGeodeWeb-Back"
-version = "5.2.0"
+version = "5.3.0-rc.1"
 dynamic = ["dependencies"]
 authors = [
   { name="Geode-solutions", email="team-web@geode-solutions.com" },
diff --git a/src/opengeodeweb_back/geode_objects.py b/src/opengeodeweb_back/geode_objects.py
index 8354d9d..43dc5d0 100644
--- a/src/opengeodeweb_back/geode_objects.py
+++ b/src/opengeodeweb_back/geode_objects.py
@@ -122,6 +122,48 @@ def geode_objects_dict():
             "save_viewable": g_v.save_viewable_hybrid_solid3D,
             "inspector": og_inspector.inspect_solid3D,
         },
+        "ImplicitCrossSection": {
+            "parent": "CrossSection",
+            "input_factory": og_gs.ImplicitCrossSectionInputFactory,
+            "output_factory": og_gs.ImplicitCrossSectionOutputFactory,
+            "missing_files": og_gs.check_implicit_cross_section_missing_files,
+            "is_loadable": og_gs.is_implicit_cross_section_loadable,
+            "load": og_gs.load_implicit_cross_section,
+            "is_saveable": og_gs.is_implicit_cross_section_saveable,
+            "save": og_gs.save_implicit_cross_section,
+            "builder": og_gs.ImplicitCrossSectionBuilder,
+            "crs": {
+                "assign": og_gs.assign_section_geographic_coordinate_system_info,
+                "convert": og_gs.convert_section_coordinate_reference_system,
+                "create": og.create_section_coordinate_system,
+            },
+            "is_model": True,
+            "is_3D": False,
+            "is_viewable": True,
+            "save_viewable": g_v.save_viewable_implicit_cross_section,
+            "inspector": og_inspector.inspect_section,
+        },
+        "ImplicitStructuralModel": {
+            "parent": "StructuralModel",
+            "input_factory": og_gs.ImplicitStructuralModelInputFactory,
+            "output_factory": og_gs.ImplicitStructuralModelOutputFactory,
+            "missing_files": og_gs.check_implicit_structural_model_missing_files,
+            "is_loadable": og_gs.is_implicit_structural_model_loadable,
+            "load": og_gs.load_implicit_structural_model,
+            "is_saveable": og_gs.is_implicit_structural_model_saveable,
+            "save": og_gs.save_implicit_structural_model,
+            "builder": og_gs.ImplicitStructuralModelBuilder,
+            "crs": {
+                "assign": og_gs.assign_brep_geographic_coordinate_system_info,
+                "convert": og_gs.convert_brep_coordinate_reference_system,
+                "create": og.create_brep_coordinate_system,
+            },
+            "is_model": True,
+            "is_3D": True,
+            "is_viewable": True,
+            "save_viewable": g_v.save_viewable_implicit_structural_model,
+            "inspector": og_inspector.inspect_brep,
+        },
         "LightRegularGrid2D": {
             "input_factory": og.LightRegularGridInputFactory2D,
             "output_factory": og.LightRegularGridOutputFactory2D,
diff --git a/tests/data/test.og_istrm b/tests/data/test.og_istrm
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index 0000000..8ef364b
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diff --git a/tests/data/test.og_ixsctn b/tests/data/test.og_ixsctn
new file mode 100644
index 0000000..105f760
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