A Pacific-wide tsunami exercise is an effective tool for evaluating the readiness of PTWS countries and to identify changes that can improve its effectiveness. The international tsunami exercises were first conceived and conducted in 2006 by the ICG/PTWS under the leadership of the PTWS Exercises Task Teams with strong contributions from the ITIC, PTWC, and JMA. Altogether there have been five IOC-coordinated international exercises, Exercise Pacific Wave 2006, 2008, 2011, 2013, and 2015. The exercises, using a multitude of Pacific scenarios and accompanied by tsunami message products from the Pacific Tsunami Warning Center, Japan Northwest Pacific Tsunami Advisory Center, and the US National Tsunami Warning Center (formerly West Coast and Alaska Tsunami Warning Center), have been used to evaluate the effectiveness of the System and measure the readiness of countries to respond, as national tsunami warning centers and emergency response agencies and the public, to distant and local tsunamis. Exercise Pacific Wave 2011, 2013, and 2015 were additionally used to introduce and obtain feedback, test, and validate the PTWC new enhanced forecast products which became official on 1 October 2014. At the 26th session the ICG/PTWS held in Honolulu, United States of America, from 22 to 24 April 2015 (ICG/PTWS-XXVI), it was agreed that the Northwest Pacific Tsunami Advisory Center (NWPTAC) should proceed with its development of enhanced products for the North West Pacific, targeting 2018 for its complete transition. At the session, it was also approved to conduct Exercise Pacific Wave 2016 (PacWave16) during the first quarter of 2016 as a regional exercise involving the sixteen countries that receive products of NWPTAC. The exercise intends to support the development of improved tsunami procedures and the NWPTAC Enhanced Products.