A captain has been charged after trying to berth a 40,000 tonne logging ship while drunk.

Police were asked by Maritime NZ to assist with a breath test on Friday following concerns the captain was intoxicated while trying to berth the ship at Port Northland - Marsden Point.

A pilot, who was assisting the docking of the ship, thought the captain of the ship appeared to be under the influence of alcohol and contacted Maritime NZ.

The ship's captain, a 53-year-old Englishman from Devon, blew what police have described as "an exceptionally high reading".

The limit for a 'seafarer' is 250 micrograms of alcohol per litre of breath and carries a 12 month term of imprisonment or a $10,000 fine.

He was subsequently arrested and charged with an offence under the Maritime Transport Act 1994 s40c - contravenes specified breath or blood-alcohol limit.

The man was remanded on bail after appearing in the Whangarei District Court this morning.

He's due to reappear on Monday.