The woman is described as having brown, greying hair, aged between 50 and 70 and was wearing a red puffer jacket with a diamond pattern to the stitching, black trousers and a white top with black lines on it.
Detective Inspector Tim Archer said: “Whilst the woman has no signs of any obvious injuries, we are keeping an open mind and treating the death as unexplained whilst we form a better picture of what has taken place.
“A red speed boat was also found tied up near to where the body was found. I would like to additionally appeal to trace the owner of this boat in case they have any further information that may assist us with our inquiries.
“If you believe you may know who the woman is, or have any information about this incident, please get in touch at the earliest opportunity.”
Anyone with information should contact police by calling 101 and quoting reference 460 of 28 June, or alternatively report online www.cambs.police.uk/report. Alternatively, contact Crimestoppers, anonymously, on 0800 555111 or via www.crimestoppers-uk.org.