The underwater world Gill Williams was once used to could be as murky and dark as some of the crimes she helped solve.
These days she immerses herself in a brighter and more colourful landscape among the spectacular wildlife beneath the waves off Skye.
Gill spent 24 years as a police diver, often involved in the gruesome task of recovering bodies from the water, or searching for missing weapons or vehicles.
First exhibition of underwater photography
Having moved to Skye after a 30-year career with the Thames Valley force, she now spends much of her time photographing the hidden treasures of the seas around the island.
Now, her first exhibition of pictures is about to be held following a three-year Below the Skyeline project exploring salt and freshwater sites.
More than 30 images from Gill and photo editor Geraint Ashton Jones feature in the event at the Skeabost House Hotel near Portree on 13 and 14 November.
Gill says her whole life has revolved around water, from learning to swim in the River Thames to her service as a police diver.
Her police work could help inquiries into murders, accidents and missing people, or finding weapons and stolen cars and bikes.
She also spent three months in Thailand working on victim identification following a devastating tsunami.
Since moving to Skye, she has set up a wild swimming group and regularly goes snorkelling, as well as climbing, sailing and kayaking.
The contrast with her more recent water-based work is stark.
“Most of the time I was working in little or no visibility, looking for something unpleasant that could often be the link in the chain to help convict someone.
‘Few people have any idea of what’s going on below the water’
“To be able to get into the water now and see what I’m looking at rather than shopping trolleys and motor bikes on the bottom is quite refreshing.
“It was always interesting but unpleasant, whereas now it’s interesting and always pleasant.”
Gill took up photography about seven years ago, turning her focus largely on the underwater world.
“Everyone coming to Skye sees the mountains and the landscape above the water – they all know what that’s like.
“But very few people have any idea of what’s going on below the water.
“While marvelling at the wonders I come across, we are also trying to raise awareness of the state of our seas and rivers in a non-political way.
“I’m constantly in awe at what I find in the depths. Geraint and I are particularly keen to draw attention to the bottom links in the food chain without which other sealife cannot survive.”
Among her memorable encounters was spotting an octopus for the first time outside the Mediterranean.
She has also swam with jellyfish and young salmon, but so far has yet to see an elusive sea horse.
Exhibition will raise money for local charities
“My biggest concern is seeing all the plastic on beaches. I’ve been involved in beach cleans, but we’re no sooner finished than it’s back again.”
Gill often visits a spawning pool where salmon lay their eggs.
“The sad thing is it’s a well-known tourist spot in the summer, full of people jumping in.
“We should give wild salmon a good chance to regenerate and lay their eggs in peace.
“I was speaking to tourists at the pool this summer. When I told them what I was photographing they were taken aback and said they wouldn’t have gone in had they known.
“So you can educate people. We are doing it by opening people’s eyes to what is down there without pushing any messages down their throat.”
The exhibition will include a chance to win some of Gill’s images. Money raised will go Skye and Lochalsh Young Carers, Crossroads Care and the Skye Food Bank.
A network of snorkel trails began in Scotland in 2016, the most recent in Lochaber this year.