The newsletter, Living Here, has a headline that says "Keeping left on the water", when traditionally boat users keep to the right when passing others on the water.
Environment Canterbury (ECan), which feared the misleading direction could create a potentially dangerous situation, has moved promptly to correct its mistake.
The standard, centuries-old national and international rule on the water was to keep right, ECan navigation safety manager Evan Walker said.
The article was written by a "non-nautical" writer, which had created the confusion about how boats should pass each other on lakes, rivers and the sea.
The story referred to ECan's website, which does have the correct information, along with other boating rules for the region's waters, which include the Waitaki lakes.
Mr Walker said ECan had 10 contracted patrol teams and 60 volunteer maritime enforcement officers over the summer period, who spent a lot of time talking to people and educating them about fundamental rules, such as keeping to the right.
However, there was still widespread ignorance.
"We see people buying jet skis who go out with absolutely no boating knowledge, so it's important for people to know the right-hand rule for the water," he said.