A young boy has tragically died following a boating incident on Sunday afternoon in the state's south.

Archie James Green was in a recreational 'sea-biscuit' flotation device being towed by a boat which lost control on the Prosser River in Orford at around 2pm on Sunday.

The 7-year-old was thrown onto rocks onshore, suffering severe head injuries and was airlifted to the Royal Hobart Hospital in a critical condition.

Authorities have now confirmed young Archie has succumbed to his injuries, two days after the accident.

A report will be prepared for the coroner.