diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index 35d81dd05..35db1b1bb 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -204,7 +204,10 @@ perimeters, terrain height, military installations and map features, plus a
 combined situation brief, military awareness around a point, the app's heads-up display caption, and a link that
 opens the app over an area. Tools reuse the layers' portable source factories, take a
 shared `area` argument (place name, bounding box, or point and radius) and cap
-lists at 25 rows by default. `aircraft_in_area` and `vessels_in_area` can also
+lists at 25 rows by default. Vessel `course_deg` and `heading_deg`, aircraft
+`course_deg`, transit `bearing_deg`, camera `heading_deg` and satellite
+`rise_azimuth_deg` and `azimuth_deg` are whole degrees from 0 to 359; a
+direction of 359.5° or more reads 0 rather than 360. `aircraft_in_area` and `vessels_in_area` can also
 count every match by a field (`group_by`: airline, read from the ICAO
 designator in the callsign, or operator, country or type for aircraft; type or
 destination for ships; the ten largest groups, then other and unknown counts;
diff --git a/src/tools/queries/aviation.js b/src/tools/queries/aviation.js
index 153e36e03..7c988c5ea 100644
--- a/src/tools/queries/aviation.js
+++ b/src/tools/queries/aviation.js
@@ -19,6 +19,7 @@ import {
   numericSummary,
   thinEvenly,
 } from '../results.js';
+import { roundHeadingDegrees } from '../../data/headingDegrees.js';
 
 const ICAO24_SCHEMA = Object.freeze({
   type: 'string',
@@ -75,7 +76,7 @@ function aircraftRow(record, from) {
     altitude_m: round(record.baroAltitudeM ?? record.ellipsoidAltitudeM, 0),
     on_ground: record.onGround === true,
     speed_mps: round(record.speedMps, 1),
-    course_deg: round(record.courseDeg, 0),
+    course_deg: roundHeadingDegrees(record.courseDeg),
     vertical_rate_mps: round(record.verticalRateMps, 1),
     type_code: record.typeCode || null,
     registration: record.registration || null,
diff --git a/src/tools/queries/aviation.test.mjs b/src/tools/queries/aviation.test.mjs
index 484719790..59a928672 100644
--- a/src/tools/queries/aviation.test.mjs
+++ b/src/tools/queries/aviation.test.mjs
@@ -146,6 +146,19 @@ test('the military feed is used on request and reported when missing', async ()
   );
 });
 
+test('an aircraft course that rounds to 360 reads as 0', async () => {
+  const catalog = composeCatalog({
+    tools: coreTools,
+    services: {
+      aircraft: feed([
+        record('ddd444', 37.6, -122.3, { callsign: 'N360', courseDeg: 359.6 }),
+      ]),
+    },
+  });
+  const result = await catalog.call('find_aircraft', { callsign: 'N360' });
+  assert.equal(result.data.rows[0].course_deg, 0);
+});
+
 test('aircraft are found by exactly one identifier across feeds', async () => {
   const catalog = composeCatalog({
     tools: coreTools,
diff --git a/src/tools/queries/maritime.js b/src/tools/queries/maritime.js
index 5798a0936..0e9d80373 100644
--- a/src/tools/queries/maritime.js
+++ b/src/tools/queries/maritime.js
@@ -20,6 +20,7 @@ import {
   numericSummary,
   thinEvenly,
 } from '../results.js';
+import { roundHeadingDegrees } from '../../data/headingDegrees.js';
 import { normalizeVesselType } from '../../data/vesselTypes.js';
 
 const MMSI_SCHEMA = Object.freeze({
@@ -57,8 +58,8 @@ function vesselRow(record, from) {
     lat: round(record.latitude, 5),
     lon: round(record.longitude, 5),
     speed_mps: round(record.speedMps, 1),
-    course_deg: round(record.courseDeg, 0),
-    heading_deg: round(record.headingDeg, 0),
+    course_deg: roundHeadingDegrees(record.courseDeg),
+    heading_deg: roundHeadingDegrees(record.headingDeg),
     observed_at: isoTime(record.observedAtMs),
     ...(from ? { distance_km: round(distanceKm(from, point), 1) } : {}),
   };
diff --git a/src/tools/queries/maritime.test.mjs b/src/tools/queries/maritime.test.mjs
index d86bdf352..f89e6bce3 100644
--- a/src/tools/queries/maritime.test.mjs
+++ b/src/tools/queries/maritime.test.mjs
@@ -351,6 +351,25 @@ test('find_vessel answers carry normalized types and destinations', async () =>
   );
 });
 
+test('a vessel course or heading that rounds to 360 reads as 0', async () => {
+  const catalog = composeCatalog({
+    tools: coreTools,
+    services: {
+      vessels: vessels({
+        records: [
+          vessel('366000003', 37.78, -122.4, {
+            courseDeg: 359.7,
+            headingDeg: 359.6,
+          }),
+        ],
+      }),
+    },
+  });
+  const [row] = (await catalog.call('find_vessel', { mmsi: '366000003' })).data
+    .rows;
+  assert.deepEqual([row.course_deg, row.heading_deg], [0, 0]);
+});
+
 test('a destination with no letters counts as unknown', async () => {
   const catalog = composeCatalog({
     tools: coreTools,
diff --git a/src/tools/queries/media.js b/src/tools/queries/media.js
index a03e88bb4..d154619db 100644
--- a/src/tools/queries/media.js
+++ b/src/tools/queries/media.js
@@ -10,6 +10,7 @@ import {
   resolveArea,
 } from '../area.js';
 import { LIMIT_SCHEMA, capRows, countNoun, toBase64 } from '../results.js';
+import { roundHeadingDegrees } from '../../data/headingDegrees.js';
 
 const FRAME_TYPES = new Set(['image/jpeg', 'image/png', 'image/webp']);
 const MAX_FRAME_BYTES = 3 * 1024 * 1024;
@@ -85,7 +86,7 @@ export const findCctvCameras = defineTool({
         provider: text(camera.provider),
         lat: round(camera.lat, 6),
         lon: round(camera.lon, 6),
-        heading_deg: round(camera.headingDeg, 0),
+        heading_deg: roundHeadingDegrees(camera.headingDeg),
         feed_type: text(camera.feedType),
         credit: text(camera.credit),
         distance_km: round(distanceKm(center, camera), 2),
diff --git a/src/tools/queries/media.test.mjs b/src/tools/queries/media.test.mjs
index 28c037a57..f690966c5 100644
--- a/src/tools/queries/media.test.mjs
+++ b/src/tools/queries/media.test.mjs
@@ -77,6 +77,20 @@ test('cameras in an area are listed nearest first', async () => {
   assert.equal(result.data.rows[1].credit, null);
 });
 
+test('a camera heading that rounds to 360 reads as 0', async () => {
+  const source = {
+    async getCatalog() {
+      return { sources: [{ ...cameras[0], headingDeg: 359.6 }] };
+    },
+  };
+  const catalog = composeCatalog({
+    tools: coreTools,
+    services: { cctv: source },
+  });
+  const result = await catalog.call('find_cctv_cameras', { area: downtown });
+  assert.equal(result.data.rows[0].heading_deg, 0);
+});
+
 test('a snapshot returns the frame as an image with its credit', async () => {
   const source = cctv();
   const catalog = composeCatalog({
diff --git a/src/tools/queries/mobility.js b/src/tools/queries/mobility.js
index 0a57ae3ae..c31f03863 100644
--- a/src/tools/queries/mobility.js
+++ b/src/tools/queries/mobility.js
@@ -19,6 +19,7 @@ import {
   resolveArea,
 } from '../area.js';
 import { LIMIT_SCHEMA, capRows, countNoun, isoTime } from '../results.js';
+import { roundHeadingDegrees } from '../../data/headingDegrees.js';
 
 const MAX_SYSTEMS = 3;
 
@@ -244,7 +245,7 @@ export const getTransitVehicles = defineTool({
         trip_id: vehicle.tripId ?? null,
         lat: vehicle.lat,
         lon: vehicle.lon,
-        bearing_deg: round(vehicle.bearing, 0),
+        bearing_deg: roundHeadingDegrees(vehicle.bearing),
         speed_mps: round(vehicle.speedMps, 1),
         status: vehicle.status ?? null,
         occupancy: vehicle.occupancy ?? null,
diff --git a/src/tools/queries/mobility.test.mjs b/src/tools/queries/mobility.test.mjs
index 0ea882727..aaaa97bad 100644
--- a/src/tools/queries/mobility.test.mjs
+++ b/src/tools/queries/mobility.test.mjs
@@ -311,6 +311,23 @@ test('transit vehicles come from nearby feeds and can be limited to a route', as
   assert.equal(rapid.data.rows[0].id, 'v2');
 });
 
+test('a transit bearing that rounds to 360 reads as 0', async () => {
+  const north = [{ ...vehicles[0], bearing: 359.6 }];
+  const catalog = composeCatalog({
+    tools: coreTools,
+    services: {
+      transit: transit({
+        ok: true,
+        status: 200,
+        json: async () => ({ vehicles: north }),
+      }),
+      clock,
+    },
+  });
+  const result = await catalog.call('get_transit_vehicles', { area: downtown });
+  assert.equal(result.data.rows[0].bearing_deg, 0);
+});
+
 test('transit reports uncovered areas and unavailable feeds', async () => {
   const catalog = composeCatalog({
     tools: coreTools,
diff --git a/src/tools/queries/space.js b/src/tools/queries/space.js
index ef59c0be5..a589e801c 100644
--- a/src/tools/queries/space.js
+++ b/src/tools/queries/space.js
@@ -10,6 +10,7 @@ import { parseTleText, tleCatalogNumber } from '../../sources/tle.js';
 import { POINT_SCHEMA, resolvePoint } from '../area.js';
 import { defineTool, ToolError } from '../catalog.js';
 import { LIMIT_SCHEMA, capRows, countNoun, isoTime } from '../results.js';
+import { roundHeadingDegrees } from '../../data/headingDegrees.js';
 
 const text = (value) => (typeof value === 'string' && value ? value : null);
 
@@ -241,7 +242,7 @@ export const nextSatellitePass = defineTool({
           peak: isoTime(pass.maxElevMs),
           set: isoTime(pass.setMs),
           max_elevation_deg: round(pass.maxElevDeg, 1),
-          rise_azimuth_deg: round(pass.riseAzDeg, 0),
+          rise_azimuth_deg: roundHeadingDegrees(pass.riseAzDeg),
           rise_direction: compass(pass.riseAzDeg),
           visible: pass.visible,
         },
@@ -283,7 +284,7 @@ export const satellitesOverhead = defineTool({
                 name: entry.name,
                 norad: entry.norad,
                 elevation_deg: round(look.elevDeg, 1),
-                azimuth_deg: round(look.azDeg, 0),
+                azimuth_deg: roundHeadingDegrees(look.azDeg),
                 direction: compass(look.azDeg),
               },
             ]
diff --git a/src/tools/queries/space.test.mjs b/src/tools/queries/space.test.mjs
index 0eb5ce346..0e44fe208 100644
--- a/src/tools/queries/space.test.mjs
+++ b/src/tools/queries/space.test.mjs
@@ -296,6 +296,24 @@ test('satellites overhead are those above the elevation, highest first', async (
   );
 });
 
+test('satellite azimuths that round to 360 read as 0', async () => {
+  const catalog = composeCatalog({
+    tools: coreTools,
+    services: { satellites: satellites(), clock: CLOCK },
+  });
+  // From these points the ISS rises at 359.7° and stands at 359.8° at CLOCK.
+  const pass = await catalog.call('next_satellite_pass', {
+    location: { lat: 10, lon: 30 },
+  });
+  assert.equal(pass.data.pass.rise_azimuth_deg, 0);
+  assert.equal(pass.data.pass.rise_direction, 'N');
+  const overhead = await catalog.call('satellites_overhead', {
+    location: { lat: 39.25, lon: 65.75 },
+  });
+  assert.equal(overhead.data.rows[0].name, 'ISS (ZARYA)');
+  assert.equal(overhead.data.rows[0].azimuth_deg, 0);
+});
+
 test('stale orbit and launch data are reported', async () => {
   const stale = {
     readGroup: async () => ({ ok: true, status: 200, text: TLE, stale: true }),