Leisure activities around New Zealand were disrupted today by a nationwide tsunami alert.



The alert was sparked by an 8.8 magnitude earthquake which struck with devastating and deadly force last night.



One of the first events affected was a mass nude photo shoot at Wellington's Breaker Bay.



Wellington City Council emergency management staff contacted the organiser of the event, scheduled for 8am today, and it was agreed the event be postponed.



City council emergency preparedness manager Fred Mecoy said the photoshoot, in which more than 100 people were expected to take part, had been cancelled due to the "obvious concerns we have about safety".



Today's dragon boat racing event on Wellington Harbour was also cancelled as a safety precaution .



Civil Defence staff and police asked the event organisers to cancel the event following reports about marked sea-level changes in the Gisborne area.



Around the country Civil defence and other emergency services were advising people to stay away from beaches and waterways, and closing boat ramps.



In Canterbury freedom campers were being evacuated from beaches and on Banks Peninsula people were moved out of the Okains Bay camping ground.



Rakaia fishing competition organisers were told of the possible tsunami about 5.30am. There were approximately 700 competitors over the length of river and Ellesmere search and rescue were advising people to move from the river mouth.



In the Bay of Plenty officials at the Ocean Athlete under-14 national surf lifesaving championships put the event on hold and advised competitors to stay away from Mount Maunganui's Main Beach after this morning's tsunami warning.



Surf Life Saving New Zealand spokesman Nathan Hight said they were taking every precaution.



"We've been monitoring the situation for the past few hours and have already told team managers to keep their athletes away from the beach until otherwise advised," Hight said.



The annual carnival has nearly 800 juniors from all over New Zealand attending.



Mount Maunganui, Omanu and Papamoa surf lifesavers were mobilised and patrolling beaches advising the public to stay away.



The Hawke's Bay Multisport Club's Ironkids Duathlon, due to take place at Ocean Spa on Napier's Marine Parade at 9am today, was cancelled due to the tsunami risk to Napier.



HB Multisport Club coordinator, Jeanette Cooper has advised people to check the club's website www.hbmsc.org.nz for more information.



Further north, in Franklin, the Kaiaua Wine and Food Festival was cancelled, and in Rodney the Mayoral Bike Challenge was also canned.



In Auckland, the Cathay Pacific half marathon and 11km race, starting at Orakei Reserve from 7am and running along Tamaki Drive was cancelled, as were the Onetangi Beach Races on Waiheke.