1 Department of Emergency Medicine, University of Florida College of Medicine-Jacksonville, 655 W 8th St, Jacksonville, FL 32209, USA; Lifeguards Without Borders, 1311A Canal Dr, Carolina Beach, NC 28428, USA. Electronic address: Andrew.schmidt@jax.ufl.edu.
2 Lifeguards Without Borders, 1311A Canal Dr, Carolina Beach, NC 28428, USA. Electronic address: jsempsrott@gmail.com.
3 Sociedade Brasileira de Salvamento Aquático, Av das Américas 3555, Bloco 2, Sala 302, Barra da Tijuca, Rio de Janeiro, RJ-22631-004, Brazil. Electronic address: David@szpilman.com.
4 Universidade Lusófona do Porto, Rua Augusto Rosa, n° 24, 4000-098, Porto, Portugal. Electronic address: acqueiroga@me.com.
5 Surf Life Saving New Zealand, PO Box 21-348, Auckland 0650, New Zealand. Electronic address: j.webber@aquasafenz.com.