Recreational ships
The skipper must have a blood alcohol limit of less than 0.05, the same rules as on the road. The skipper is also responsible for the safety of the passengers and should be responsible for their alcohol consumption. The effects of alcohol are enhanced while on the water due to the sun, wind, waves and constant motion. Reflexes and response times to emergencies are slowed and swimming ability deteriorates considerably.

Skippers of recreational boats should also be aware that, when their boat is anchored, it may still be considered to be used for navigation, and the blood alcohol limit applies. The limit does not change unless the boat is securely moored in a marina, to a jetty or wharf or on a swing mooring.

Commercial ships
The rules for commercial ships are different to those for recreational ships. The blood alcohol limit for a skipper whilst in charge of a class 1 commercial ship is zero.

Section 79 of the Transport Operations (Road Use Management) Act 1995 (PDF, 1.2MB) refers to driving and so on whilst under influence of liquor or drugs or with prescribed concentration of alcohol in blood or breath.

Suspension of a marine licence
If the holder of any marine licence has been convicted of a drink driving offence in a road motor vehicle, their marine licence can be cancelled or suspended.