sandbox: Journal 131 has gone to press and is due for publication in September 2025
CREG Journal 131 (0-24)
This issue has a cover date of September 2025 and was published on 1 September 2025.

Front Cover (1)
Ken Smith places a Pinger in an air bell in an underwater cave in the Nullarbor Plain, Australia. Photo: <span class="author">Dr Richard Harris</span>

Contents (2)
List of contents and masthead information.

News and Notes (2)
Autumn 2025 Field Meeting, Hidden Earth, Editorial Team.

The Technology of Cave Diving Habitats (3-7)
<span class="author">Andy Pitkin</span> introduces the technology involved in the habitats that cave divers use for decompression after deep dives. Included here are breathing gas management, minimising the fire risk and communication.

Pinger 2.0: an Updated Transmitter for Radiolocation in Flooded Passages &#40;Part 1&#41; (8-10)
Following their description of a new cylindrical coil antenna in the previous issue, <span class="author">Aren Leishman</span> and <span class="author">Ken Smith</span> and provide details of the associated new transmitter circuit.

ResCon 25 (11)
Technology was on show at the recent ResCon rescue conference. <span class="author">Tony Haigh</span> reports.

Using VLF Geophysics for Detecting New Cave Systems (12-16)
<span class="author">Atanas Rusev</span> describes the use of VLF geophysics as an effective tool in cave detection. He illustrates this with several case studies that show how the technology has been used in the field.

How to Modify the Cave-Link Menus (17-20)
<span class="author">Christopher Ross</span> describes how to modify the Cave-Link menus to suit your specific needs.

Could Caves Hold the Key to Earthquake Prediction? (21-24)
<span class="author">Matt Rowberry</span> and <span class="author">Ivo Baro&ncaron;</span> from the Czech Academy of Sciences and Tom&aacute;&scaron; Tr&ccaron;ka from Brno University	of Technology describe the tricky process of detecting rock	strain induced electromagnetic anomalies in caves.