Tidal anomalies at Taiaroa Head

Port Otago shipping was uninterrupted by yesterday's tsunami alert, but several 10cm-30cm "tidal anomalies" were registered at Taiaroa Head in five hours after 10am.

Port Otago operations manager Ron Horner said "normal contingencies", including briefing stevedores and the masters of ships in port, took place following national alerts.

"Being a low tide, a 0.5m surge would be within the normal tidal range," Mr Horner said.

A tidal "anomaly" of a dip in sea levels followed by a "30cm surge" was reported at Taiaroa Head about 10am, with several more smaller surges between 10cm and 20cm registering, he said.

"There's been only very minor effects in Port Chalmers and none in Dunedin," Mr Horner said.

The container vessel Cap Bianco arrived at 7.30am as scheduled yesterday and berthed at Port Chalmers without incident, with the ship's master having taken the decision to go ahead with berthing "based on the information he had", Mr Horner said.

At the Ports of Auckland, all commercial vessels were evacuated from the Waitemata seaport to a deeper harbour yesterday morning.

Harbour cruises, fishing competitions and yachting regattas were all either cancelled or curtailed yesterday as organisers erred on the side of caution in light of the tsunami alert.

Monarch Wildlife Cruises owner John Milburn said five cruises scheduled from Wellers Rock and two half-day cruises had been cancelled.

Mr Milburn said he first heard the news early yesterday on the radio, and contacted crew to move the Monarch from its mooring to prevent damage.

Information from harbour control and Maritime New Zealand advised not to attempt the cruises, and Mr Milburn said he felt "duty-bound" to comply.

The company had lost between $2000 and $3000 from the cancellations, but that was "just one of those things", he said.

An annual salmon fishing competition in Dunedin, run by the Otago branch of the New Zealand Salmon Anglers Association, was scaled back yesterday.

Chairman Wayne Olsen said organisers had got the message out to skippers in the morning to advise them not to go out yesterday.

Shore-based anglers carried on.

A yachting regatta on Otago harbour was called off after advice from police.

Police emergency response group manager Inspector Alistair Dickie said organisers "were "persuaded" not to go ahead after concerns were raised about the possibility of waves coming past Quarantine Island and "that there would be enough to tip a boat on its side".

Yesterday's tsunami warning in South Otago was initially met with a reaction of disbelief.

Jenny Mason, of Pounawea, was woken at 5am by her brother-in-law in Koitiata, near Whanganui, with a text saying there was a tsunami warning.

She said her response was: "I hope you are not joking".

Mrs Mason was one of 50 people staying at Pounawea's Keswick Park and Convention Centre when the warning came.

Owaka Fire Service chief fire officer Mark Cuthbert was woken by a phone call from Owaka Constable Murray Hewitson at 5.30am.

"He said 'There's a tsunami warning'.

[My] brain [was] still half asleep at 5:30am, and [I'm] thinking, 'What sort of wind up joke is this?'."

Joking turned to frustration when people refused to listen to warnings.

Owaka fireman Dean Madden said he met people on the road who said they were going down to the beach to watch the tsunami.