Radio amateurs from the Radio Society of Sri Lanka (RSSL) will participate in the Indian Ocean Wave 2025 exercise (IOWave25), coordinated by UNESCO’s intergovernmental coordination group for Indian Ocean tsunamis on November 5, 2025. RSSL will support the Disaster Management Centre by operating HF and VHF emergency communication networks during the exercise, which is intended to test tsunami preparedness and communication readiness across Indian Ocean nations. 

RSSL is requesting all amateur radio stations within the International Amateur Radio Union Region 3 keep the following HF frequencies clear and give priority to emergency communication traffic related to the exercise between 0800 – 1600 LKT (0230–1030 UTC). IARU R3 includes the Pacific and parts of Asia.

See image for a short list of the frequencies involved.

For more information and additional information about the exercise, contact the Radio Society of Sri Lanka (RSSL) – www.rssl.lk/emergency.

ARRL thanks IARU Region 3 Secretary Ken Yamamoto, JA1CJP, for sharing information included in this announcement.