diff --git a/Assets/Scripts/ServerShared/GravityField.cs b/Assets/Scripts/ServerShared/GravityField.cs
index 53c2755a0..71e1f0c2a 100644
--- a/Assets/Scripts/ServerShared/GravityField.cs
+++ b/Assets/Scripts/ServerShared/GravityField.cs
@@ -11,7 +11,9 @@ using float2 = CultMath.float2;
 public static class GravityField
 {
     // The potential at distance r from the body, defined up to a constant (callers subtract their reference).
+    // A well of no strength (a body whose curves are unauthored, so c = 0 and R = 0) digs nothing.
     public static float Potential(float c, float coreRadius, float r) =>
+        c == 0f ? 0f :
         r < coreRadius
             ? c * r * r / (2 * coreRadius * coreRadius)
             : c * (log(r / coreRadius) + .5f);
diff --git a/tests/Aetheria.Shared.Tests/FloatingBodyTests.cs b/tests/Aetheria.Shared.Tests/FloatingBodyTests.cs
index fbf68bf79..b86ef459f 100644
--- a/tests/Aetheria.Shared.Tests/FloatingBodyTests.cs
+++ b/tests/Aetheria.Shared.Tests/FloatingBodyTests.cs
@@ -184,7 +184,7 @@ public sealed class FloatingBodyTests : IDisposable
             QualityPriceModifier = new ExponentialLerp()
         };
         var items = new ItemManager(cache, new ProvenanceLedger(), settings, _ => { });
-        var planets = new PlanetSettings();
+        var planets = new PlanetSettings { HeightExaggeration = 10f }; // the tilt reads force / K, which K = 1 would hide
         var pack = new ZonePack { Radius = 1000 };
         WellFixture.Dig(cache, pack, planets, 300, 100);
         zone = new Zone(items, planets, pack, new GalaxyZone { Name = "Test Zone", Owner = null }, null);
diff --git a/tests/Aetheria.Shared.Tests/PotentialOwnerTests.cs b/tests/Aetheria.Shared.Tests/PotentialOwnerTests.cs
index e1d6e8606..7111bccb4 100644
--- a/tests/Aetheria.Shared.Tests/PotentialOwnerTests.cs
+++ b/tests/Aetheria.Shared.Tests/PotentialOwnerTests.cs
@@ -73,6 +73,24 @@ public sealed class PotentialOwnerTests : IDisposable
     // The law written out: potential c r^2 / 2R^2 inside the core, c (ln(r / R) + 1/2) beyond.
     private static float Phi(float c, float core, float r) => r < core ? c * r * r / (2 * core * core) : c * (log(r / core) + .5f);
 
+    // A zone whose bodies have no authored gravity curves (most test zones) has no pull and no dip, and no NaN either.
+    [Fact]
+    public void BodiesWithNoAuthoredWellPullAndDigNothing()
+    {
+        var planets = new PlanetSettings
+        {
+            BodyRadius = new ExponentialCurve(), GravityRadius = new ExponentialCurve(), GravityDepth = new ExponentialCurve(),
+            LightRadius = new ExponentialCurve(), OrbitPeriod = new ExponentialCurve()
+        };
+        var zone = ZoneOf(planets, (100f, float2.zero), (5000f, new float2(200f, 0f)));
+        foreach (var p in new[] { float2.zero, float2(200f, 0f), float2(37f, -911f), float2(5000f, 5000f) })
+        {
+            Assert.Equal(0f, zone.GetHeight(p));
+            Assert.Equal(0f, zone.GetForce(p).x);
+            Assert.Equal(0f, zone.GetForce(p).y);
+        }
+    }
+
     [Fact]
     public void StrengthFollowsTheAuthoredMassCurve()
     {