diff --git a/apple/Sources/FerrostarCore/Extensions/CoreLocation Extensions.swift b/apple/Sources/FerrostarCore/Extensions/CoreLocation Extensions.swift
index ddf637fc..7ff1ae18 100644
--- a/apple/Sources/FerrostarCore/Extensions/CoreLocation Extensions.swift	
+++ b/apple/Sources/FerrostarCore/Extensions/CoreLocation Extensions.swift	
@@ -61,12 +61,14 @@ extension CourseOverGround {
     /// Intialize a Course Over Ground object from the relevant Core Location types. These can be found on a
     /// CLLocation object.
     ///
+    /// This returns nil if the course or courseAccuracy are invalid as defined by Apple (negative)
+    ///
     /// - Parameters:
     ///   - course: The direction the device is travelling, measured in degrees relative to true north.
     ///   - courseAccuracy: The accuracy of the direction
     public init?(course: CLLocationDirection,
                  courseAccuracy: CLLocationDirectionAccuracy) {
-        guard course > 0 && courseAccuracy > 0 else {
+        guard course >= 0 && courseAccuracy >= 0 else {
             return nil
         }
         
@@ -78,12 +80,12 @@ extension Heading {
     
     /// Initialize a Heading if it can be represented as integers
     ///
-    /// This will return nil for invalid headings.
+    /// This returns nil if the heading or accuracy  are invalid as defined by Apple (negative)
     ///
     /// - Parameter clHeading: The CoreLocation heading provided by the location manager.
     public init?(clHeading: CLHeading) {
-        guard clHeading.trueHeading > 0
-            && clHeading.headingAccuracy > 0 else {
+        guard clHeading.trueHeading >= 0
+            && clHeading.headingAccuracy >= 0 else {
             return nil
         }
         
@@ -95,8 +97,43 @@ extension Heading {
 
 extension UserLocation {
     
+    /// Initialize a UserLocation from values.
+    ///
+    /// - Parameters:
+    ///   - latitude: The latitude in decimal degrees
+    ///   - longitude: The longitude in decimal degrees
+    ///   - horizontalAccuracy: The horizontal accuracy
+    ///   - course: The direction of travel measured in degrees clockwise from north.
+    ///   - courseAccuracy: The course accuracy measured in degrees.
+    ///   - timestamp: The timestamp of the location record.
+    public init(latitude: CLLocationDegrees,
+                longitude: CLLocationDegrees,
+                horizontalAccuracy: CLLocationDistance,
+                course: CLLocationDirection,
+                courseAccuracy: CLLocationDirectionAccuracy,
+                timestamp: Date) {
+        
+        self.init(coordinates: GeographicCoordinate(lat: latitude, lng: longitude),
+                  horizontalAccuracy: horizontalAccuracy,
+                  courseOverGround: CourseOverGround(course: course, courseAccuracy: courseAccuracy),
+                  timestamp: timestamp)
+    }
+    
+    /// Initialize a UserLocation with a coordinate only.
+    ///
+    /// - Parameter clCoordinateLocation2D: A core location coordinate.
+    public init(clCoordinateLocation2D: CLLocationCoordinate2D) {
+        // This behavior matches how CLLocation initializes with a coordinate (setting accuracy to 0 & date to now)
+        self.init(coordinates: GeographicCoordinate(cl: clCoordinateLocation2D),
+                  horizontalAccuracy: 0,
+                  courseOverGround: nil,
+                  timestamp: Date())
+    }
+    
     /// Initialize a UserLocation from an Apple CoreLocation CLLocation
     ///
+    /// Unlike CourseOverGround & Heading, this value will init with invalid values.
+    ///
     /// - Parameter clLocation: The location.
     public init(clLocation: CLLocation) {
         self.init(
diff --git a/apple/Sources/FerrostarCore/FerrostarCore.swift b/apple/Sources/FerrostarCore/FerrostarCore.swift
index 1b92f1f3..5e9ab6fb 100644
--- a/apple/Sources/FerrostarCore/FerrostarCore.swift
+++ b/apple/Sources/FerrostarCore/FerrostarCore.swift
@@ -237,7 +237,7 @@ public protocol FerrostarCoreDelegate: AnyObject {
             case .complete:
                 // TODO: "You have arrived"?
                 self.state?.visualInstructions = nil
-                self.state?.snappedLocation = UserLocation(clLocation: location)  // We arrived; no more snapping needed
+                self.state?.snappedLocation = UserLocation(clLocation: location)! // TODO: Handle error?  // We arrived; no more snapping needed
                 self.state?.courseOverGround = CourseOverGround(course: location.course, courseAccuracy: location.courseAccuracy)
                 self.state?.spokenInstruction = nil
             }
diff --git a/apple/Sources/FerrostarCore/Mock/MockNavigationState.swift b/apple/Sources/FerrostarCore/Mock/MockNavigationState.swift
new file mode 100644
index 00000000..8e1e057c
--- /dev/null
+++ b/apple/Sources/FerrostarCore/Mock/MockNavigationState.swift
@@ -0,0 +1,94 @@
+import Foundation
+import CoreLocation
+import UniFFI
+
+extension NavigationState {
+    public static let pedestrianExample = NavigationState(
+        snappedLocation: CLLocation(latitude: samplePedestrianWaypoints.first!.latitude,
+                                    longitude: samplePedestrianWaypoints.first!.longitude),
+        fullRoute: samplePedestrianWaypoints,
+        steps: []
+    )
+
+    public static func modifiedPedestrianExample(droppingNWaypoints n: Int) -> NavigationState {
+        let remainingLocations = Array(samplePedestrianWaypoints.dropFirst(n))
+        let lastUserLocation = remainingLocations.first!
+
+        var result = NavigationState(
+            snappedLocation: CLLocation(latitude: samplePedestrianWaypoints.first!.latitude,
+                                        longitude: samplePedestrianWaypoints.first!.longitude),
+            fullRoute: samplePedestrianWaypoints,
+            steps: [UniFFI.RouteStep(
+                geometry: [lastUserLocation.geographicCoordinates],
+                distance: 100, roadName: "Jefferson St.",
+                instruction: "Walk west on Jefferson St.",
+                visualInstructions: [
+                    UniFFI.VisualInstruction(
+                        primaryContent: VisualInstructionContent(text: "Hyde Street", maneuverType: .turn, maneuverModifier: .left, roundaboutExitDegrees: nil),
+                        secondaryContent: nil, triggerDistanceBeforeManeuver: 42.0)
+                ],
+                spokenInstructions: [])
+            ])
+
+        result.snappedLocation = UserLocation(
+            coordinates: GeographicCoordinate(lat: samplePedestrianWaypoints.first!.latitude,
+                                              lng: samplePedestrianWaypoints.first!.longitude),
+            horizontalAccuracy: 10,
+            courseOverGround: CourseOverGround(degrees: 0, accuracy: 10),
+            timestamp: Date()
+        )
+
+        return result
+    }
+}
+
+// Derived from the Stadia Maps map matching example
+private let samplePedestrianWaypoints = [
+    CLLocationCoordinate2D(latitude: 37.807770999999995, longitude: -122.41970699999999),
+    CLLocationCoordinate2D(latitude: 37.807680999999995, longitude: -122.42041599999999),
+    CLLocationCoordinate2D(latitude: 37.807623, longitude: -122.42040399999999),
+    CLLocationCoordinate2D(latitude: 37.807587, longitude: -122.420678),
+    CLLocationCoordinate2D(latitude: 37.807527, longitude: -122.420666),
+    CLLocationCoordinate2D(latitude: 37.807514, longitude: -122.420766),
+    CLLocationCoordinate2D(latitude: 37.807475, longitude: -122.420757),
+    CLLocationCoordinate2D(latitude: 37.807438, longitude: -122.42073599999999),
+    CLLocationCoordinate2D(latitude: 37.807403, longitude: -122.420721),
+    CLLocationCoordinate2D(latitude: 37.806951999999995, longitude: -122.420633),
+    CLLocationCoordinate2D(latitude: 37.806779999999996, longitude: -122.4206),
+    CLLocationCoordinate2D(latitude: 37.806806, longitude: -122.42069599999999),
+    CLLocationCoordinate2D(latitude: 37.806781, longitude: -122.42071999999999),
+    CLLocationCoordinate2D(latitude: 37.806754999999995, longitude: -122.420746),
+    CLLocationCoordinate2D(latitude: 37.806739, longitude: -122.420761),
+    CLLocationCoordinate2D(latitude: 37.806701, longitude: -122.42105699999999),
+    CLLocationCoordinate2D(latitude: 37.806616999999996, longitude: -122.42171599999999),
+    CLLocationCoordinate2D(latitude: 37.806562, longitude: -122.42214299999999),
+    CLLocationCoordinate2D(latitude: 37.806464999999996, longitude: -122.422123),
+    CLLocationCoordinate2D(latitude: 37.806453, longitude: -122.42221699999999),
+    CLLocationCoordinate2D(latitude: 37.806439999999995, longitude: -122.42231),
+    CLLocationCoordinate2D(latitude: 37.806394999999995, longitude: -122.422585),
+    CLLocationCoordinate2D(latitude: 37.806305, longitude: -122.423289),
+    CLLocationCoordinate2D(latitude: 37.806242999999995, longitude: -122.423773),
+    CLLocationCoordinate2D(latitude: 37.806232, longitude: -122.423862),
+    CLLocationCoordinate2D(latitude: 37.806152999999995, longitude: -122.423846),
+    CLLocationCoordinate2D(latitude: 37.805687999999996, longitude: -122.423755),
+    CLLocationCoordinate2D(latitude: 37.805385, longitude: -122.42369),
+    CLLocationCoordinate2D(latitude: 37.805371, longitude: -122.423797),
+    CLLocationCoordinate2D(latitude: 37.805306, longitude: -122.42426999999999),
+    CLLocationCoordinate2D(latitude: 37.805259, longitude: -122.42463699999999),
+    CLLocationCoordinate2D(latitude: 37.805192, longitude: -122.425147),
+    CLLocationCoordinate2D(latitude: 37.805184, longitude: -122.42521199999999),
+    CLLocationCoordinate2D(latitude: 37.805096999999996, longitude: -122.425218),
+    CLLocationCoordinate2D(latitude: 37.805074999999995, longitude: -122.42539699999999),
+    CLLocationCoordinate2D(latitude: 37.804992, longitude: -122.425373),
+    CLLocationCoordinate2D(latitude: 37.804852, longitude: -122.425345),
+    CLLocationCoordinate2D(latitude: 37.804657, longitude: -122.42530599999999),
+    CLLocationCoordinate2D(latitude: 37.804259, longitude: -122.425224),
+    CLLocationCoordinate2D(latitude: 37.804249, longitude: -122.425339),
+    CLLocationCoordinate2D(latitude: 37.804128, longitude: -122.425314),
+    CLLocationCoordinate2D(latitude: 37.804109, longitude: -122.425461),
+    CLLocationCoordinate2D(latitude: 37.803956, longitude: -122.426678),
+    CLLocationCoordinate2D(latitude: 37.803944, longitude: -122.42677599999999),
+    CLLocationCoordinate2D(latitude: 37.803931, longitude: -122.42687699999999),
+    CLLocationCoordinate2D(latitude: 37.803736, longitude: -122.42841899999999),
+    CLLocationCoordinate2D(latitude: 37.803695, longitude: -122.428411),
+]
diff --git a/apple/Sources/FerrostarCore/NavigationState.swift b/apple/Sources/FerrostarCore/NavigationState.swift
index f7be48c3..073d6f0c 100644
--- a/apple/Sources/FerrostarCore/NavigationState.swift
+++ b/apple/Sources/FerrostarCore/NavigationState.swift
@@ -19,102 +19,12 @@ public struct NavigationState: Hashable {
     public internal(set) var isCalculatingNewRoute: Bool = false
 
     init(snappedLocation: CLLocation, heading: CLHeading? = nil, fullRoute: [CLLocationCoordinate2D], steps: [RouteStep]) {
-        self.snappedLocation = UserLocation(clLocation: snappedLocation)
+        self.snappedLocation = UserLocation(clLocation: snappedLocation)! // TODO: Handle an error here if UserLocation is invalid?
         if let heading {
             self.heading = Heading(clHeading: heading)
         }
-        self.courseOverGround = CourseOverGround(course: snappedLocation.course,
-                                                 courseAccuracy: snappedLocation.courseAccuracy)
-        self.fullRouteShape = fullRoute.map { GeographicCoordinate(lat: $0.latitude, lng: $0.longitude) }
+        self.courseOverGround = self.snappedLocation.courseOverGround
+        self.fullRouteShape = fullRoute.map { GeographicCoordinate(cl: $0) }
         self.currentStep = steps.first!
     }
-
-    public static let pedestrianExample = NavigationState(
-        snappedLocation: CLLocation(latitude: samplePedestrianWaypoints.first!.latitude,
-                                    longitude: samplePedestrianWaypoints.first!.longitude),
-        fullRoute: samplePedestrianWaypoints,
-        steps: []
-    )
-
-    public static func modifiedPedestrianExample(droppingNWaypoints n: Int) -> NavigationState {
-        let remainingLocations = Array(samplePedestrianWaypoints.dropFirst(n))
-        let lastUserLocation = remainingLocations.first!
-
-        var result = NavigationState(
-            snappedLocation: CLLocation(latitude: samplePedestrianWaypoints.first!.latitude,
-                                        longitude: samplePedestrianWaypoints.first!.longitude),
-            fullRoute: samplePedestrianWaypoints,
-            steps: [UniFFI.RouteStep(
-                geometry: [lastUserLocation.geographicCoordinates],
-                distance: 100, roadName: "Jefferson St.",
-                instruction: "Walk west on Jefferson St.",
-                visualInstructions: [
-                    UniFFI.VisualInstruction(
-                        primaryContent: VisualInstructionContent(text: "Hyde Street", maneuverType: .turn, maneuverModifier: .left, roundaboutExitDegrees: nil),
-                        secondaryContent: nil, triggerDistanceBeforeManeuver: 42.0)
-                ],
-                spokenInstructions: [])
-            ])
-
-        result.snappedLocation = UserLocation(
-            coordinates: GeographicCoordinate(lat: samplePedestrianWaypoints.first!.latitude,
-                                              lng: samplePedestrianWaypoints.first!.longitude),
-            horizontalAccuracy: 10,
-            courseOverGround: CourseOverGround(degrees: 0, accuracy: 10),
-            timestamp: Date()
-        )
-
-        return result
-    }
 }
-
-// Derived from the Stadia Maps map matching example
-private let samplePedestrianWaypoints = [
-    CLLocationCoordinate2D(latitude: 37.807770999999995, longitude: -122.41970699999999),
-    CLLocationCoordinate2D(latitude: 37.807680999999995, longitude: -122.42041599999999),
-    CLLocationCoordinate2D(latitude: 37.807623, longitude: -122.42040399999999),
-    CLLocationCoordinate2D(latitude: 37.807587, longitude: -122.420678),
-    CLLocationCoordinate2D(latitude: 37.807527, longitude: -122.420666),
-    CLLocationCoordinate2D(latitude: 37.807514, longitude: -122.420766),
-    CLLocationCoordinate2D(latitude: 37.807475, longitude: -122.420757),
-    CLLocationCoordinate2D(latitude: 37.807438, longitude: -122.42073599999999),
-    CLLocationCoordinate2D(latitude: 37.807403, longitude: -122.420721),
-    CLLocationCoordinate2D(latitude: 37.806951999999995, longitude: -122.420633),
-    CLLocationCoordinate2D(latitude: 37.806779999999996, longitude: -122.4206),
-    CLLocationCoordinate2D(latitude: 37.806806, longitude: -122.42069599999999),
-    CLLocationCoordinate2D(latitude: 37.806781, longitude: -122.42071999999999),
-    CLLocationCoordinate2D(latitude: 37.806754999999995, longitude: -122.420746),
-    CLLocationCoordinate2D(latitude: 37.806739, longitude: -122.420761),
-    CLLocationCoordinate2D(latitude: 37.806701, longitude: -122.42105699999999),
-    CLLocationCoordinate2D(latitude: 37.806616999999996, longitude: -122.42171599999999),
-    CLLocationCoordinate2D(latitude: 37.806562, longitude: -122.42214299999999),
-    CLLocationCoordinate2D(latitude: 37.806464999999996, longitude: -122.422123),
-    CLLocationCoordinate2D(latitude: 37.806453, longitude: -122.42221699999999),
-    CLLocationCoordinate2D(latitude: 37.806439999999995, longitude: -122.42231),
-    CLLocationCoordinate2D(latitude: 37.806394999999995, longitude: -122.422585),
-    CLLocationCoordinate2D(latitude: 37.806305, longitude: -122.423289),
-    CLLocationCoordinate2D(latitude: 37.806242999999995, longitude: -122.423773),
-    CLLocationCoordinate2D(latitude: 37.806232, longitude: -122.423862),
-    CLLocationCoordinate2D(latitude: 37.806152999999995, longitude: -122.423846),
-    CLLocationCoordinate2D(latitude: 37.805687999999996, longitude: -122.423755),
-    CLLocationCoordinate2D(latitude: 37.805385, longitude: -122.42369),
-    CLLocationCoordinate2D(latitude: 37.805371, longitude: -122.423797),
-    CLLocationCoordinate2D(latitude: 37.805306, longitude: -122.42426999999999),
-    CLLocationCoordinate2D(latitude: 37.805259, longitude: -122.42463699999999),
-    CLLocationCoordinate2D(latitude: 37.805192, longitude: -122.425147),
-    CLLocationCoordinate2D(latitude: 37.805184, longitude: -122.42521199999999),
-    CLLocationCoordinate2D(latitude: 37.805096999999996, longitude: -122.425218),
-    CLLocationCoordinate2D(latitude: 37.805074999999995, longitude: -122.42539699999999),
-    CLLocationCoordinate2D(latitude: 37.804992, longitude: -122.425373),
-    CLLocationCoordinate2D(latitude: 37.804852, longitude: -122.425345),
-    CLLocationCoordinate2D(latitude: 37.804657, longitude: -122.42530599999999),
-    CLLocationCoordinate2D(latitude: 37.804259, longitude: -122.425224),
-    CLLocationCoordinate2D(latitude: 37.804249, longitude: -122.425339),
-    CLLocationCoordinate2D(latitude: 37.804128, longitude: -122.425314),
-    CLLocationCoordinate2D(latitude: 37.804109, longitude: -122.425461),
-    CLLocationCoordinate2D(latitude: 37.803956, longitude: -122.426678),
-    CLLocationCoordinate2D(latitude: 37.803944, longitude: -122.42677599999999),
-    CLLocationCoordinate2D(latitude: 37.803931, longitude: -122.42687699999999),
-    CLLocationCoordinate2D(latitude: 37.803736, longitude: -122.42841899999999),
-    CLLocationCoordinate2D(latitude: 37.803695, longitude: -122.428411),
-]
diff --git a/apple/Sources/FerrostarMapLibreUI/MapLibre Extensions.swift b/apple/Sources/FerrostarMapLibreUI/MapLibre Extensions.swift
index 6bea748e..4aef616b 100644
--- a/apple/Sources/FerrostarMapLibreUI/MapLibre Extensions.swift	
+++ b/apple/Sources/FerrostarMapLibreUI/MapLibre Extensions.swift	
@@ -4,11 +4,11 @@ import MapLibre
 
 extension NavigationState {
     var routePolyline: MLNPolyline {
-        return MLNPolylineFeature(coordinates: fullRouteShape.map { CLLocationCoordinate2D(latitude: $0.lat, longitude: $0.lng) })
+        return MLNPolylineFeature(coordinates: fullRouteShape.map { $0.clLocationCoordinate2D })
     }
 
     var remainingRoutePolyline: MLNPolyline {
         // FIXME
-        return MLNPolylineFeature(coordinates: fullRouteShape.map { CLLocationCoordinate2D(latitude: $0.lat, longitude: $0.lng) })
+        return MLNPolylineFeature(coordinates: fullRouteShape.map { $0.clLocationCoordinate2D })
     }
 }
diff --git a/apple/Tests/FerrostarCoreTests/FerrostarCoreModelTests.swift b/apple/Tests/FerrostarCoreTests/FerrostarCoreModelTests.swift
deleted file mode 100644
index e69de29b..00000000
diff --git a/apple/Tests/FerrostarCoreTests/Models/CoreLocationModelTests.swift b/apple/Tests/FerrostarCoreTests/Models/CoreLocationModelTests.swift
index 57b44885..3a519bbe 100644
--- a/apple/Tests/FerrostarCoreTests/Models/CoreLocationModelTests.swift
+++ b/apple/Tests/FerrostarCoreTests/Models/CoreLocationModelTests.swift
@@ -62,7 +62,23 @@ final class CoreLocationModelTests: XCTestCase {
         XCTAssertEqual(userLocation.timestamp, timestamp)
     }
     
-    // TODO: Decide methodology for invalid CLLocation data (negatives)
+    func testInvalidInitUserLocation() {
+        let timestamp = Date()
+        let coordinate = CLLocationCoordinate2D(latitude: -77.846323, longitude: 166.668235)
+        let location = CLLocation(coordinate: coordinate,
+                                  altitude: 10,
+                                  horizontalAccuracy: -1.1,
+                                  verticalAccuracy: 6.6,
+                                  course: 45.5,
+                                  courseAccuracy: 3.3,
+                                  speed: 4.4,
+                                  speedAccuracy: 1.1,
+                                  timestamp: timestamp)
+        
+        let invalid = UserLocation(clLocation: location)
+        
+        XCTAssertNil(invalid)
+    }
     
     // MARK: CourseOverGround
     
diff --git a/common/ferrostar/src/models.rs b/common/ferrostar/src/models.rs
index cb909d7a..df51aaf0 100644
--- a/common/ferrostar/src/models.rs
+++ b/common/ferrostar/src/models.rs
@@ -72,29 +72,6 @@ pub struct Heading {
     pub timestamp: SystemTime,
 }
 
-impl Heading {
-
-    /// Create a new heading.
-    /// 
-    /// # Arguments
-    /// 
-    /// * `true_heading` - The heading relative to true north, measured in clockwise degrees from
-    /// true north (N = 0, E = 90, S = 180, W = 270).
-    /// * `accuracy` - The maximum deviation in degrees between the reported heading and the true geomagnetic heading.
-    /// * `timestamp` - The time at which the heading was recorded.
-    pub fn new(
-        true_heading: u16,
-        accuracy: u16,
-        timestamp: SystemTime,
-    ) -> Self {
-        Self {
-            true_heading,
-            accuracy,
-            timestamp,
-        }
-    }
-}
-
 /// The direction in which the user/device is observed to be traveling.
 #[derive(Clone, Copy, PartialEq, PartialOrd, Debug, uniffi::Record)]
 pub struct CourseOverGround {
@@ -124,26 +101,6 @@ pub struct UserLocation {
     pub timestamp: SystemTime,
 }
 
-impl UserLocation {
-    pub fn new(
-        latitude: f64,
-        longitude: f64,
-        horizontal_accuracy: f64,
-        course_over_ground: Option<CourseOverGround>,
-        timestamp: SystemTime,
-    ) -> Self {
-        Self {
-            coordinates: GeographicCoordinate { 
-                lat: latitude, 
-                lng: longitude 
-            },
-            horizontal_accuracy,
-            course_over_ground,
-            timestamp,
-        }
-    }
-}
-
 impl From<UserLocation> for Point {
     fn from(val: UserLocation) -> Point {
         Point::new(val.coordinates.lng, val.coordinates.lat)