With summer coming the message has gone out for Whanganui River users to be safe and be seen.
Trevor Gibson, chairman of the Whanganui Navigation and Water Safety Group, said too many river users were flouting basic navigation rules while others were not making a big enough effort to be easily seen in or on the river.
Mr Gibson said the river becoming increasingly popular as a recreational spot meant more traffic on the water.
"We're urging swimmers especially to consider wearing brightly coloured caps to make them more visible to other river users.
"And we want those in boats, whether powered or not, or jet ski users to observe the basic maritime rules of keeping to the right hand side of the river at all times."