Two men who smashed a jetski into a barge wreck sparked a rescue drama on Tauranga harbour.

Both were taken to hospital with a variety of injuries, after the high-speed crash onto rusting steel and concrete.

An off-duty nurse attends to the injured jetski skipper on the barge deck.

Witnesses say they were concerned before the incident, about the conduct of the personal watercraft.

Boaties on the beach in Hunters Creek on Sunday say the jetski, with two aboard, had been seen speeding close to harbour markers and the iconic barge wreck, when the jetski appeared to lose control and crash into the steel and concrete remains.

Tauranga Coastguard's two vessels were on a training exercise in the Omokoroa area when they received a call to attend, about 3pm. The harbourmaster's patrol boat also was on the scene.

Tauranga Coastguard at the scene of today's crash.

The jetski passenger, believed to be aged 19, was taken from the barge by the Coastguard's vessel, Sealegs Rescue, and transferred to the Coastguard's 13m launch, TECT Rescue.

The Sealegs then made a second trip back to the barge to take on board the driver of the jetski, believed to be a man aged in his forties. He had facial and abdominal injuries and was unable to stand or walk, after impacting at speed on the handlebars of the PWC and onto the barge wreck. The patient was transferred from the barge deck by stretcher, to Sealegs Rescue, and taken to a waiting ambulance at Sulphur Point Marina.

Other PWC users and waterskiers on the beach helped at the scene, including a nurse, Jan, who administered first aid to the jetski driver on the barge until he was uplifted by the Coastguard.

They said the young man had arm injuries and seemed to be in shock. The older man, understood to be the skipper, had facial contusions and pelvic area injuries, thought to be from impact with the jetski handlebars.

The jetski was severely damaged in the bow section.

The barge wreck in Hunters Creek is an iconic landmark, on a sandbank west of the Matakana Island ski lane. The former munitions storage vessel has been grounded between Matakana and Rangiwaea Island for around 40 years and gradually deteriorating.

The steel hull's back broke many decades ago, leaving part of the rusting steel hulk above water and the concrete block storage structure gradually crumbling into the sea.

As one of the few sheltered ski lanes in Tauranga harbour, it is a popular spot for personal water craft, skiers and water toys. The barge also narrows the gap between it and the island.

Witnesses on the beach today say unless everyone adheres to the 'anticlockwise” rule, keeping to the right, then problems can occur.

They say it's not the first time they've had concerns about the skipper's behaviour and how close the craft was speeding near markers and the barge wreck.