A search and rescue volunteer for over sixty years in Papua New Guinea outlines the benefits of having an EPIRB when on the open sea.
A VHF radio is useful for communicating with other nearby boats and harbourmasters, but in remote areas without line-of-sight communication, an EPIRB is a cost-effective and more robust alternative if you run into difficulties.
VHF radios are waterproof, but will not transmit underwater, while a handheld EPIRB will alert search and rescue authorities via satellite, often within minutes of being activated.
Read more here:
https://www.thenational.com.pg/its-the-locator-beacon-not-vhf-radio-that-will-save-your-life/