"The males indicated they had been travelling up the river when they got caught out by low water and lack of light," police said, adding the vessel was equipped with flares, a radio and lifejackets.
A vehicle and boat trailer was nearby. However, as the pair had been drinking they were advised not to drive and to make other arrangements.
But 15 minutes later, the vehicle and boat trailer was stopped by police with one of the men behind the steering wheel.
"He failed a breath screening test and was processed for drink driving," police said.
The Queenstown harbour master has been advised of the boating incident.