The New Zealand Defence Force says the member of the elite Special Operations Force who died this morning while conducting an exercise was Sergeant Wayne Taylor.
Sergeant Taylor died during a maritime counter-terrorism training exercise off the coast of Coromandel Peninsula, the NZDF said in a statement.
He joined the Royal New Zealand Infantry Regiment as a member of the Army Reserve in 1993 — joining the Regular Force in October 1997, serving in East Timor and Afghanistan.
"Many of the Regiment, both RNZIR and NZSAS, will remember him as an outstanding soldier, leader, father, family man, and friend to many, as well as being an all-round top bloke," Major General Peter Kelly Chief of Army said.
"He was a consummate professional, who was known for his dedication and reliability — always upholding our core values in every endeavour."
Sergeant Taylor is survived by his wife and four children.
Two witnesses told 1 NEWS they saw flares fired into the sky this morning after three inflatable boats rushed onto shore at Port Jackson.
The injured soldier was being cared for on the beach with CPR being performed.
The Westpac Helicopter was called to the incident and dropped paramedics on to the beach about 6.30am.
"I saw the boats come in a flare went up, soon after the rescue helicopter landed," one witness said, who did not want to be identified.
A man was transported to Auckland Hospital by helicopter.
The witness also said they have noticed military training activity in the area "from time to time" and "I saw a frigate out there yesterday".
"It's a very quiet area" they said.
"It's very sad to think someone has lost their life out there today."
Defence Minister Mark Mitchell has released a statement following the incident where he offers condolences and pays tribute to the fallen soldier.
"No words can adequately describe this sudden and tragic loss. Your family member was a man who commanded high respect amongst his fellow soldiers and embodied the Army's core values of courage, commitment, comradeship and integrity," Mr Mitchell said.
"This is a tragedy not only for the family, but for every member of the Defence Force. My thoughts are also with them today."
Sergeant Taylor's next of kin have been informed, the NZDF said, and they also expressed their sympathies.
New Zealand Police has been informed of the incident.
NZDF's website describes the Special Operations Force as being involved in "pre-empting threats to New Zealand and its interests and providing military special operations support to domestic, regional and global security situations".