The Cave Screen

The live map fills the screen. Across the top: Guide Lines, Measure, 2D/3D, Layers and the torch, with the compass top right. Along the bottom: the readout on the left (the XYZ widget above it in 3D), then Follow, Snap and, in the Navigator, Go on the right. Follow centers the map on you; tap it again once centered (2D, north locked) to switch heading-up and north-up. You are the blue dot, the red cone shows which way you face. Tap the map to hide the tools; double tap fits the view. Layers: compass, XYZ widget, station labels, 3D grid. Station dots can be hidden too. Every button is in the Icon Directory.

With the entrance and north locked and no line recording, the cave screen is the Navigator: every line tied to this entrance, the entrance (ENT) and your live position. The readout gives the nearest station, depth, distance from the entrance and the drift at your last snap. Every line starts off: switch on the ones you want in Guide Lines. Tap Go to be routed to a station along the survey (Navigator and Go). The ON LINE / OFF LINE chip (5 m) buzzes when you leave and when you come back. Nothing is recorded.

Lines drift, most after tracking is lost or along an imported survey. Stand on a known point, tap Snap and pick from the Snap To list: Entrance & Datums first, then every line (the recording one open), nearest first with distances, and a search. A point that can't be placed from here is grayed with the reason. Your position jumps to it, the heading is corrected when the points are far enough apart, and the drift shows in the readout. Snapping doesn't pause the line. Right here re-zeroes where you stand without moving the line. After time in the background, POSITION UNSURE asks you to snap.

While recording, POSITION UNSURE also shows if tracking runs away in a dark or blank passage: SpeleoMap holds the line on the last good point instead of drawing a jump, and Snap lights up. Hold still or add light, then snap.

If SpeleoMap closes underground (a crash or a dead battery), the new workout can't lock north in the cave. Start it anyway (skip north), tap New Cave Line, pick a station from before the crash under Start at and tap Inherit calibration. Stand near the station and face the way its faded photo does: SpeleoMap matches the view, checks the compass and locks on its own; then tap Begin. New lines then line up with the old survey. Any station from a trip with the entrance GPS works: one with north gives north back; a State B one ties you into that trip without north (a trip with north can't inherit from a State B station). If the photo and the compass disagree, it asks: Use photo match or Use compass. If the view won't match at all (No photo match), it offers the compass, or try another station. In the Navigator, Snap lists other trips' stations under OTHER TRIPS · INHERIT.

Multi (legs and total), Shot (from you: distance, true bearing, inclination), Along (following a line) and Height. Taps snap to stations, pins or the line. The eraser clears. The live map is scratch: nothing is saved. To keep a measurement, measure on the line's page and tap Save.