A group of New Year's Eve drinkers may have the legal high ground after they built a sand island in a Coromandel estuary to get around a local liquor ban.

The group planted a table and benches on their mound at low tide at Tairau on Sunday to create a public drinking outpost when the tide came in. That was despite a peninsula-wide ban on public consumption of alcohol.

The group reportedly told bystanders they weren't subject to the law because they were in "international waters".

Liquor ban areas, which can include beaches, are dictated by councils.

Thames Coromandel Mayor Sandra Goudie was amused by the incident and did not believe the island - which was eventually eroded by the tide - fell under her council's jurisdiction.

"It appears to be harmless and doesn't seem to be hurting anybody. It's probably watch, wait and see. The novelty will probably wear off."

It would probably take a legal challenge to determine whether the group had successfully got around the ban, but she wouldn't be keeping an eye on it.

"There's always something else to do."

Harbourmaster Stephen Wise was also laughing at the incident.

The island was defined as inland waters, he told NZ Newswire.

"There's no liquor ban for boaties... unless something happens then they can get prosecuted."

He wasn't quite sure what action could be taken if more people adopted the tactic.

Police were not commenting on the matter.

- NZ Newswire