Volunteer divers guard Oman's coral reefs

On a sailing boat anchored off Oman's pristine Daymaniyat Islands, volunteer divers pull on wetsuits, check their scuba tanks and then take turns plunging into the clear turquoise water.

They are diving for a reason: to remove the massive fishing nets damaging an unusually resilient coral reef system that is seen as more likely than most to survive rising sea temperatures.