Relieving yourself over the side of a boat could soon be banned in parts of the Marlborough Sounds.
A proposed new rule, part of Marlborough District Council's Marlborough Environment Plan, means boaties would have to be 1km off shore, rather than 500 metres, before they can discharge their untreated sewerage.
Also in the plan is a new 1km restriction for the discharge of untreated sewage near marine farms.
If adopted, the plan would come into effect on June 9, 2022.
Boat owner Ian Logan, who lives on his boat Eluder, told the Marlborough Express that urinating into the sea was common practice among sailors.
And the twisted Sounds coastline meant it was difficult to find a spot 1km from land.
"When you've got to go, you've got to go, it's human nature," Logan said.
"Out here where would be more than 1km away from land either side, if you're out in the middle you've got strong tides running which are going to dissipate it anyway."
Marlborough District Council environmental policy manager Pere Hawes told the Express the rules were included to address concerns of groups such as iwi and marine farmers.