diff --git a/handbook/index.htm b/handbook/index.htm
index 4f9754d7d..c4af2eec1 100644
--- a/handbook/index.htm
+++ b/handbook/index.htm
@@ -30,6 +30,7 @@ Need to get in touch with someone? Look here.
 <ul>
   <li><a href="phone.htm">Phone numbers and setup</a> - Topcamp and basecamp numbers, adding credit.</li>
   <li><a href="rescue.htm">Rescue</a> - How and when to call rescue. (read before you need!)</li>
+  <li><a href="cavelink.html">Cavelink</a> - The VLF radio system that enables communication between topcamp and underground.</li>
 </ul>
 <hr>
 
diff --git a/handbook/phone.htm b/handbook/phone.htm
index 1bfa2973f..6e19b1607 100644
--- a/handbook/phone.htm
+++ b/handbook/phone.htm
@@ -52,6 +52,8 @@ It is charged using a standard microUSB charger.
 
 <p>Bascamp phone is a Nokia phone which requires a unique Nokia charger to which it is <i>permanently connected</i> in the potato hut.
 
+<h3>Cavelink</h3>
+<p>New in 2019 is the <a href="cavelink.html">Cavelink system</a> which communicates between topcamp and a station in a cave. The topcamp end has a SIM which means that it can receive and send text messages.
 <h3>Annual renewal</h3>
 <p>This has to be done in less than 13 months otherwise it costs a more as you
 essentially have to start from scratch (~&euro;10 for a new SIM with &euro;5 of