Surface to entrance and back.

Before your trip, open Settings → Hike to set your preferences for the surface portion of the trip:

• Map style. Standard, Satellite, Hybrid, or Topographic
• Trail cadence. how frequently GPS points are recorded (10 seconds or 10 meters, whichever comes first)
• Coordinate format. decimal degrees, DMS, UTM, or MGRS
• Route sharing. how Hike Lines export for sharing

See Settings for a full walkthrough.

From the home screen, tap New Project. One project holds the whole trip — Hike Lines, cave survey workouts, scans, photos, and notes all live together. If you're starting with a hike in before a cave survey, create the project here at the car.

Planning to do a Cave Survey on the same trip? Create one project and run both workouts inside it.

Hike Line requires State C calibration. GPS position and true north lock. SpeleoMap walks you through two steps:

• GPS fix. wait for the accuracy to converge. Outdoors this typically takes under 30 seconds. The tighter the fix, the more accurate your trail line and destination bearings.
• True north lock. hold the phone steady while SpeleoMap reads the magnetometer. If the compass won't stabilize, move away from any metal (car, fence, gear). A figure-eight motion can help recalibrate the iOS compass.

Precise Location must be enabled in iOS Settings for Hike Line to work. Approximate Location is not sufficient.

Once calibrated, tap Start Hike. SpeleoMap opens the live map and begins recording your trail. Apple Health tracking activates automatically — heart rate, active calories, and elevation gain are recorded for the duration of the hike.

See Apple Health for what gets recorded.

SpeleoMap records your path as a live GPS line over Apple Maps. The line updates in real time as you move. Where GPS signal is strong the line is solid — in heavy tree canopy or canyons where signal drops, SpeleoMap dead-reckons using the IMU and magnetometer to keep the line continuous, then snaps back to GPS when signal returns.

Map styles — Standard, Satellite, Hybrid, and Topographic — are selectable during the hike. Switch to compass mode when map tiles won't load in areas without cell service.

Enter a destination coordinate in any format — decimal degrees, DMS, UTM, MGRS, an Apple Maps URL, or a geo: URI. SpeleoMap shows a live bearing line and distance to the destination on the map, updating as you move. No cell routing required — works fully offline once the destination is set.

Tap and hold on the map to drop a pin at any point — a trailhead, a dig, a cave entrance, a feature worth noting. Each pin gets a name and notes. Pins are GPS-anchored and appear on the map alongside your trail line.

Share any pin as an Apple Maps URL via Messages, AirDrop, or any share destination. One tap sends the coordinate to anyone — works whether they have SpeleoMap or not.

On iPhone Pro or Pro Max, tap Scan at any point on the hike to capture a 3D LiDAR scan of anything interesting — a cliff face, a cave entrance, a geological feature. The scan is GPS-anchored and heading-referenced, and appears as a pin on your trail map. Tap the pin to open the 3D viewer.

See LiDAR for more detail on scanning.

Capture photos and add notes at any point on the trail, anchored to your GPS position. See Photos & Video and Notes & Annotations.

Switch between the live map, a top-down plan view, an elevation over time profile, and a 3D view at any point during the hike — without stopping the recording. Check your elevation gain, review a pin, or look at the trail shape so far.

The Details tab is available at any time — rename the project, update team names, add trip notes, or check your hike totals.

At the cave entrance, end the Hike Line workout before starting your cave survey. This keeps the surface and underground data cleanly separated in the same project. The Apple Health workout closes with your total hike time, distance, and elevation gain.

Ready to go underground? See Cave Survey for what comes next.

After ending your cave survey at the entrance, start a new Hike Line for the hike back to the car. It lives in the same project alongside your cave survey workout — the full trip, surface to surface, in one place.

Back at the car, export your Hike Line as GPX for Gaia GPS or CalTopo, KML for Google Earth, or the native SpeleoMap bundle. The surface approach and the cave below it can sit on the same map. See Export.