A ceremony on a Manly ferry which resulted in a person's ashes blowing on to passengers was allowed to proceed despite public health concerns because of the deceased's close affinity with Sydney's ferries.

The minute-long scattering ceremony reportedly went slightly awry on a windy April 11 when one of the iconic vessels stopped near South Head on the crossing to Manly.

You can now pay for your Manly Ferry ride with a tap-and-go credit card. Credit:Ben Rushton

A spokeswoman for Harbour City Ferries told AAP on Wednesday the company does not usually allow ashes to be scattered from its vessels "given public health and safety concerns".

"In general, we usually say no, unless there is quite a deep, personal connection to the ferries," she said in a statement.