diff --git a/experiments/2025-03-18/src/geometry/curve.rs b/experiments/2025-03-18/src/geometry/curve.rs
index 52ef895b0..7a5f030f6 100644
--- a/experiments/2025-03-18/src/geometry/curve.rs
+++ b/experiments/2025-03-18/src/geometry/curve.rs
@@ -29,7 +29,9 @@ impl AnchoredCurve {
     ) -> Self {
         Self {
             origin,
-            floating: Box::new(curve),
+            floating: FloatingCurve {
+                inner: Box::new(curve),
+            },
         }
     }
 
@@ -50,17 +52,19 @@ impl AnchoredCurve {
     }
 
     pub fn point_from_local(&self, point: impl Into<Point<1>>) -> Point<3> {
-        self.origin + self.floating.vector_from_local_point(point.into())
+        self.origin + self.floating.inner.vector_from_local_point(point.into())
     }
 
     pub fn project_point(&self, point: Point<3>) -> Point<1> {
-        self.floating.project_vector(point - self.origin)
+        self.floating.inner.project_vector(point - self.origin)
     }
 
     pub fn translate(&self, offset: impl Into<Vector<3>>) -> Self {
         Self {
             origin: self.origin + offset,
-            floating: self.floating.clone_curve_geometry(),
+            floating: FloatingCurve {
+                inner: self.floating.inner.clone_curve_geometry(),
+            },
         }
     }
 
@@ -69,7 +73,7 @@ impl AnchoredCurve {
         boundary: [Point<1>; 2],
         tolerance: Tolerance,
     ) -> Vec<Point<1>> {
-        self.floating.approximate(boundary, tolerance)
+        self.floating.inner.approximate(boundary, tolerance)
     }
 }
 
@@ -77,12 +81,16 @@ impl Clone for AnchoredCurve {
     fn clone(&self) -> Self {
         Self {
             origin: self.origin,
-            floating: self.floating.clone_curve_geometry(),
+            floating: FloatingCurve {
+                inner: self.floating.inner.clone_curve_geometry(),
+            },
         }
     }
 }
 
-pub type FloatingCurve = Box<dyn CurveGeometry>;
+pub struct FloatingCurve {
+    pub inner: Box<dyn CurveGeometry>,
+}
 
 pub trait CurveGeometry {
     fn clone_curve_geometry(&self) -> Box<dyn CurveGeometry>;
diff --git a/experiments/2025-03-18/src/geometry/swept_curve.rs b/experiments/2025-03-18/src/geometry/swept_curve.rs
index 23d5ec543..c032344fa 100644
--- a/experiments/2025-03-18/src/geometry/swept_curve.rs
+++ b/experiments/2025-03-18/src/geometry/swept_curve.rs
@@ -17,7 +17,7 @@ impl SweptCurve {
 
         Self {
             u: AnchoredCurve::from_origin_and_curve(origin, u),
-            v: Box::new(v),
+            v: FloatingCurve { inner: Box::new(v) },
         }
     }
 
@@ -29,7 +29,7 @@ impl SweptCurve {
     pub fn point_from_local(&self, point: impl Into<Point<2>>) -> Point<3> {
         let [u, v] = point.into().coords.components;
         self.u.point_from_local([u])
-            + self.v.vector_from_local_point(Point::from([v]))
+            + self.v.inner.vector_from_local_point(Point::from([v]))
     }
 
     pub fn project_point(&self, point: impl Into<Point<3>>) -> Point<2> {
@@ -39,7 +39,9 @@ impl SweptCurve {
         let v = {
             let v = AnchoredCurve {
                 origin: self.u.point_from_local(u),
-                floating: self.v.clone_curve_geometry(),
+                floating: FloatingCurve {
+                    inner: self.v.inner.clone_curve_geometry(),
+                },
             };
 
             v.project_point(point)
@@ -51,14 +53,18 @@ impl SweptCurve {
     pub fn flip(&self) -> Self {
         Self {
             u: self.u.clone(),
-            v: self.v.flip(),
+            v: FloatingCurve {
+                inner: self.v.inner.flip(),
+            },
         }
     }
 
     pub fn translate(&self, offset: impl Into<Vector<3>>) -> Self {
         Self {
             u: self.u.translate(offset),
-            v: self.v.clone_curve_geometry(),
+            v: FloatingCurve {
+                inner: self.v.inner.clone_curve_geometry(),
+            },
         }
     }
 }
diff --git a/experiments/2025-03-18/src/model.rs b/experiments/2025-03-18/src/model.rs
index c433c48c3..dd6368e4a 100644
--- a/experiments/2025-03-18/src/model.rs
+++ b/experiments/2025-03-18/src/model.rs
@@ -3,7 +3,7 @@ use fj_math::Vector;
 use fj_viewer::Viewer;
 
 use crate::{
-    geometry::{Line, Sketch, SweptCurve, ToTriMesh},
+    geometry::{FloatingCurve, Line, Sketch, SweptCurve, ToTriMesh},
     handle::Handle,
     operations::sweep::SweepExt,
     topology::surface::Surface,
@@ -45,9 +45,11 @@ pub fn model(viewer: &Viewer) -> TriMesh {
     viewer.display(top.to_tri_mesh(tolerance));
 
     let solid = top.sweep(
-        Box::new(Line {
-            direction: Vector::from([0., 0., -2.]),
-        }),
+        FloatingCurve {
+            inner: Box::new(Line {
+                direction: Vector::from([0., 0., -2.]),
+            }),
+        },
         [1.],
     );
     viewer.display(solid.to_tri_mesh(tolerance));
diff --git a/experiments/2025-03-18/src/operations/connect.rs b/experiments/2025-03-18/src/operations/connect.rs
index 7b4356663..03e0ac698 100644
--- a/experiments/2025-03-18/src/operations/connect.rs
+++ b/experiments/2025-03-18/src/operations/connect.rs
@@ -88,7 +88,9 @@ fn build_connecting_faces(
             let curve = Curve {
                 geometry: AnchoredCurve {
                     origin: a.point,
-                    floating: connecting_curve.clone_curve_geometry(),
+                    floating: FloatingCurve {
+                        inner: connecting_curve.inner.clone_curve_geometry(),
+                    },
                 },
             };
 
diff --git a/experiments/2025-03-18/src/operations/sweep.rs b/experiments/2025-03-18/src/operations/sweep.rs
index 7808c386c..0e6538728 100644
--- a/experiments/2025-03-18/src/operations/sweep.rs
+++ b/experiments/2025-03-18/src/operations/sweep.rs
@@ -26,7 +26,7 @@ pub trait SweepExt {
 impl SweepExt for Handle<Face> {
     fn sweep(self, along: FloatingCurve, to: impl Into<Point<1>>) -> Solid {
         let [from, to] = [Point::from([0.]), to.into()]
-            .map(|point| along.vector_from_local_point(point));
+            .map(|point| along.inner.vector_from_local_point(point));
 
         let bottom = self;
         let top = {