An urgent mission is underway in Kaikoura to recover a boat that has run aground 200m offshore, sparking fears of a diesel spill in the delicate world-renowned ecosystem.

The Environment Canterbury (ECan) coastal response team was alerted late this morning to a 40-foot vessel that ran aground off the Kaikōura coast overnight.

It ran aground approximately 200m offshore.

Four crew members were rescued and are said to be "safe and well".

Current weather is not helping with the recovery. Photo / Supplied

"The vessel has multiple steel fuel tanks with around 1300 litres of diesel on board," said ECan regional on-scene commander Emma Parr.

"We aware of the delicate ecosystem in this area and are working to minimise any potential impact."

The current weather is not favourable, with a strong cold southerly.

The owner of the vessel, along with help from locals, are attempting to tow the vessel, with plans for fuel removal and salvage of the vessel, Parr said.

"We will be working with other response agencies throughout the day," she added.

Kaikōura is world-famous for its wide range of important native species and ecosystems, including NZ fur seals, whales and dolphins, with whale-watching tours a major tourist attraction.