Boys will wear specially-fitted full-face scuba masks, plus wetsuits, boots and helmets

Diver will guide boys through cave using an 8mm static rope

They receive air from navy diver's tank

Navy diver

‘Stage tanks’ filled with air also placed along route

Boys will wear specially-fitted full-face scuba masks, plus wetsuits, boots and helmets

They receive air from navy diver's tank

Diver will guide boys through cave using an 8mm static rope

‘Stage tanks’ filled with air also placed along route

Navy diver

Boys will wear specially-fitted full-face scuba masks, plus wetsuits, boots and helmets

They receive air from navy diver's tank

Diver will guide boys through cave using an 8mm static rope

‘Stage tanks’ filled with air also placed along route

Navy diver