Underground, start to finish.

Before your trip, open Settings and review your survey preferences. These stay set between sessions so you only need to adjust them when something changes.

• Profile → Appearance. color scheme (Dark / Light / Greyscale), units (metric or imperial), station pin colors, coordinate display format, 3D grid opacity
• Scanning. scan quality and waypoint density. Higher quality = larger files. Tune for your device and trip length
• Workout. activity type (Caving, Hiking, etc.) and whether to track heart rate
• Calibration. drift tolerance threshold
• Warnings & Alerts. motion coaching, thermal sensitivity, battery alerts
• Photos & Video. whether photos mirror to your iOS Photos app

Also check your iOS compass calibration — Settings → Privacy → Location Services → System Services → Compass Calibration. A well-calibrated compass improves your true-north lock at the entrance.

See Settings for a full walkthrough.

From the home screen, tap New Project. Projects are auto-named by date but you can rename them anytime. One project holds everything from a trip — the hike in, multiple cave survey workouts, the hike out, photos, scans, and notes all live together.

Before you leave the trailhead, start a Hike Line to record your approach to the cave. The hike in is part of the trip — surface GPS, elevation profile, pins for features along the way, and your entrance coordinates all live in the same project as your cave survey.

End the Hike Line at the cave entrance before you start your cave survey workout.

At the cave entrance, SpeleoMap acquires your GPS position. Watch the accuracy reading — the tighter the fix, the better your georeferenced export. Tap Lock This Fix when you're satisfied.

This entrance coordinate is the anchor for your entire survey. It enables true-north bearings, Survex declination, and world georeferencing. You can't recapture it underground — lock it before you drop in.

SpeleoMap has three calibration states:

• State A. no calibration. Bearings are relative to your start point. Good for a quick sketch.
• State B. GPS lock at entrance. Shared project origin. Bearings still local.
• State C. GPS + true north lock. Bearings are true-north referenced. Survex export includes declination. Your survey is georeferenceable to a world map.

State C is recommended for any survey you plan to keep. Temporarily mark your datum point with a small piece of flagging tape — crew members can use the same piece to tie in throughout the trip. Remove it before you leave. No tape behind.

Tap Start Survey to begin. This activates Apple Health tracking alongside your cave data — heart rate, active calories, flights climbed, and depth are all recorded for the duration of the trip. The workout runs in the background so the phone can sleep between stations.

See Apple Health for what gets recorded.

Tap New Map Line to begin recording your survey traverse. SpeleoMap records your path continuously as you move. Hold the phone naturally — since Build 25 the heading is correct regardless of how you hold it.

You can run multiple Map Lines in one workout — one per passage, one per crew member, or one per survey leg. Each line is independent and labeled automatically (A, B, C...).

As you move through the cave, tap to drop pins at key points along your Map Line:

• Stations. survey benchmarks, passage junctions, climb tops, hazards. Auto-labeled (S1, S2...). Add names, notes, and photos to any station. See Notes & Annotations.
• Scans. capture a 3D LiDAR point cloud of the passage around you (iPhone Pro only). Start and stop stations drop automatically. See LiDAR.
• Photos & Video. capture media anchored to your position on the Map Line. See Photos & Video.
• Notes & Annotations. drop text notes, hazard markers, and cartographic symbols anywhere on the line. See Notes & Annotations.

Tape lines record manual measurement legs between stations — useful for cross-passages, offsets, or any shot where you want a precise distance that isn't along your walked traverse. Every tape point becomes a survey station on the active Map Line.

When you can't hold the phone, put it in your pack or pocket and press the home button or swipe up to background the app — do not close it. SpeleoMap keeps recording your path via the workout session running in the background, switching from ARKit to step counting to track distance through the crawl. When you emerge, bring the app back to the foreground, give it a second to settle, then drop a station.

Pack mode records an open traverse — accuracy comes from the mode itself, not closure. Your logs after every trip help improve it.

You can review your Map Line, stations, and scans at any point during the workout without stopping the recording. Switch to the map view, check your traverse, measure passage dimensions from a scan, or review a photo at a station — all while the line keeps recording.

The Details tab is available at any time during the workout — rename the project, update team names, add trip notes, or check your entrance GPS and calibration status.

You don't have to wait until you're back at camp. Export a line or share a project bundle to a teammate's device via AirDrop at any point during the trip. Crew members can import a bundle and tie their own lines into the same project in the field.

See Export and Import.

Before you start hiking out, tap End Survey at the cave entrance. SpeleoMap finalizes the workout — saving all Map Lines, stations, scans, photos, and notes to the project. The Apple Health workout record closes with your total time, distance, and health metrics.

Ending the workout at the entrance rather than at the trailhead keeps your cave survey data separate from the hike out. If you want to record the hike out, start a Hike Line after ending the survey.