Yellow cave marker cookie — underground route marking

Yellow caving cookie: route marker for underground progression

In karst cave systems where visibility drops to a few metres and every junction looks like the last, a well-placed route marker can be the difference between a clean exit and a prolonged disorientation. This yellow caving cookie is designed to mark the key waypoints of an underground route — gallery junctions, sump entries, passage intersections — using a highly visible colour that reads clearly even under the low-angle beam of a caving headlamp in deep cave conditions.

Design and field use

The caving cookie (also known as a progression marker or gallery tag) is a core accessory for organised caving. Its yellow colour provides strong contrast against the grey and brown limestone walls typical of European karst systems, allowing fast visual identification of the marking line even in low-light conditions. The compact format allows discrete placement on walls, formations or fixed rigging without obstructing the passage of subsequent teams.

In sump diving, caving cookies are used alongside the guideline to indicate exit directions, passage forks and points of interest in flooded sections. Marking conventions used in underground exploration generally distinguish directional markers (arrows) from position markers (round cookies), with each colour potentially indicating a team, a direction or a hazard level depending on the protocol agreed by the group.

User profiles and applications

This yellow cookie is primarily intended for cavers exploring complex multi-team systems, sump divers marking their progression along a guideline, and cave rescue teams who need to quickly relocate a marked route during an intervention. Yellow is frequently used as the primary reference colour or as an alert colour, depending on the local conventions of the club or exploration team.

In high-traffic cave systems — training caves and practice sites — colour-coded cookie marking allows multiple teams to operate simultaneously on separate routes without risk of confusion, each team adopting its own reference colour for the duration of the trip.

Key features

• High-visibility yellow: effective contrast against limestone walls and under headlamp illumination, for fast visual identification even in low-light conditions.
• Compact and lightweight: easy to carry in large quantities in a caving pack, with negligible weight penalty on extended explorations.
• Versatile use: suitable for marking dry galleries and flooded sump passages on a guideline.
• Junction and position marker: usable as a gallery junction cookie, passage intersection tag or sump exit indicator, depending on the team's agreed protocol.

For more information on underground progression equipment not subject to PPE certification requirements, see our Proteushop guide to non-PPE diving and caving equipment.