A team of 16- and 17-year-olds at Yeshivat Amit Nachshon school near Beit Shemesh has set up a startup to develop a wrist band that aims to help keep beach-goers safe from drowning. Life guards will be alerted if someone is swimming out too far or if showing signs of distress.

https://www.timesofisrael.com/beach-boys-high-schoolers-startup-aims-to-develop-wrist-band-for-water-safety/