He went under water during an exercise on Tregantle beach on Tuesday evening and was airlifted to hospital, according to authorities.
A Royal Navy spokesperson has now confirmed he has died.
“We can confirm the sad death of the Royal Marine who was injured in an incident earlier this week and we now ask for a period of grace for the family,” a Royal Navy spokesperson has said.
“The thoughts and sympathies of the Naval Service go out to the family and friends of the individual.”
A man was taken by air ambulance to Derriford Hospital in Plymouth, Devon, after going underwater on 21 January, South Western Ambulance Service said earlier this week.
It is understood that the name of the recruit will not be released by the MoD for at least 24 hours and only with the permission of his family.
The navy spokesperson said the incident concerning the death of the recruit is under investigation.
Additional reporting by Press Association