In light of the current implications re: Coronavirus, the Caribe Wave 2020 Task Team and Officers of the ICG have agreed that for the Caribe Wave 2020 RTSP (PTWC) will only provide products to facilitate a communications test. The Intergovernmental Coordination Group for the Tsunami and Other Coastal Hazards Warning System for the Caribbean and Adjacent Regions at its eighth session (ICG/CARIBE EWS-VIII, Port of Spain, Trinidad and Tobago, 29 April–1 May 2013), decided to conduct tsunami exercises named CARIBE WAVE on an annual basis leaving each Member State to define its level of participation. At its fourteenth session (Punta Leona, Costa Rica, 8–11 April 2019), the ICG/CARIBE-EWS, recommended that Exercise CARIBE WAVE 20 take place on 19 March 2020 at 14:00:00 UTC (Coordinated Universal Time) with the following two hypothetical earthquake and tsunami scenarios: • A tsunami generated by a magnitude 8.0 earthquake located on the Enriquillo-Plantain Garden Fault Zone in Jamaica • A transoceanic tsunami generated by a magnitude 8.5 earthquake located off the coast of Portugal The purpose of this exercise is to practice and evaluate the operations of the CARIBE-EWS Tsunami Warning System along the coasts of the Caribbean and adjacent regions. It provides an opportunity to evaluate the Pacific Tsunami Warning Center Enhanced Products for the Tsunami and other Coastal Hazards Warning System for the Caribbean and Adjacent Regions and the corresponding readiness of emergency management organizations and communities at risk including operational lines of communications, tsunami response procedures, and evacuation procedures, and promote tsunami preparedness at community level. Regular exercising of response plans is critical to maintain readiness for an emergency. All Emergency Management Organizations are encouraged to participate and involve the communities at risk. The US Pacific Tsunami Warning Center (PTWC) will issue one initial dummy message on 19 March 2020 at 14:00 UTC, and will disseminate it over all standard Tsunami Warning Centre broadcast channels. This dummy message shall be issued to test communications with Tsunami Warning Focal Points (TWFPs) and National Tsunami Warning Centres (NTWC), and to start the exercise. Then at 14:07 UTC, the PTWC will send by email the simulated tsunami text products to officially designated TWFPs and NTWCs according to the chosen scenario. Each TWFP/NTWC will decide how to disseminate the messages within their area of responsibility. In cases where a Member State does not inform the PTWC and CTWP, the organizers will decide on the scenario. The ICG/CARIBE-EWS of UNESCO/IOC, the US National Oceanic and Atmospheric Administration (NOAA), and the Caribbean Regional Stakeholders (CEPREDENAC, CDEMA, and EMIZA) are providing the framework for this exercise as a means for emergency responders throughout the Caribbean and adjacent regions to test and update tsunami response plans. The participant handbook with details of the exercise is attached to this circular letter and available online at http://www.caribewave.info. Additional information relevant to the exercise will also be posted on this link in due course. For CARIBE WAVE 20, the CARIBE-EWS organization team has teamed up with TsunamiZone.org for an online registration at http://tsunamizone.org/caribbean. Under the ‘Caribbean Zone Region’ tab, participants can sign up as of January 2020, and will receive a participation confirmation email. Emergency Management Organizations (EMOs) will have real-time access to the status of participants’ registration within their areas of responsibility. EMOs are encouraged to promote this registration system. During CARIBE WAVE 19, of almost 800,000 total participants, over 500,000 used the TsunamiZone.org page to register. Online seminars for orienting participants on the exercise are offered in English, Spanish and French languages, and scheduled on 21–23 January and 26–28 February 2020. Registration to seminars is at http://www.caribewave.info.