The head of an expert underwater forensics team drafted into the search for Nicola Bulley says if she drowned in the River Wyre his sonar will likely find her “immediately”.
Peter Faulding, founder of Specialist Group International, has offered his services to Lancashire Police for free.
The 45-year-old mum disappeared on a dog walk in St Michaels on Wyre on January 27.
Her springer spaniel Willow was found wandering along the route near a bench where her owner's phone had been left, overlooking the water.
Surrey-based SGI - which normally charges around £4,000 a day - will be launching its ‘top of the market’ 18,000khz side scan sonar later this morning.
Mr Faulding believes if Nicola went into the river and drowned she would have likely got "snagged" within around 500 metres of the point of entry.
Mr Faulding told the Mirror: “If Nicola is in there, we will find her. If she’s there, our sonar will pick her up straight away.
“I will see a body on the bottom. We are dealing with about 10 drownings every summer. We always locate within the hour. It’s that quick, it’s that good.
“Nicola wouldn’t have gone far if she was in this river because it’s got shallows and she would get lodged. There’s no way she would have gone out to the estuary.
"The river’s not in flood, it’s benign.”
Mr Faulding said if Nicola fell into the river and was conscious, cold water shock could have “taken her breath away” and her energy would have been sapped meaning she would eventually drown.
It would then take a few days for a body to resurface as it decomposes, unless it is caught on something.
But he said if she was fit and healthy and a reasonable swimmer, she could have pulled herself out, if not at the point of entry further down the bank.
"She wouldn’t have been dragged down, no way,” he continued.
"There is apparently quite a deep pool in the middle there.
"She wouldn’t have been swept away, the clothing she was wearing, it wasn’t heavy wool so it wouldn’t absorb water so quickly as normal clothing."
Mr Faulding said the police likely do have similar sonar but it probably isn't as powerful as his team's and they likely don't have the same level of expertise and personnel to focus on using it.
Explaining how the equipment works, he said: "The sonar will highlight every stick and stone on the bottom.
"It’s as good as that.
"As I tow it along I get a picture on the screen in front of me.
"The sound wave gets sent across the river bed and then that data gets picked up and comes back and is analysed by the computer, and I can actually measure how long a target is. We can then put a diver in to confirm that target."
However, Mr Faulding is not convinced Nicola is in the water.
“She could have potentially floated and also there were no screams heard or anything," he said.
“Normally people would scream out and I don’t know if there was other people in the area but you’d scream out, you’d flap around and the dog would normally maybe stay with the owner. There’s something, in my opinion, not quite right here.”
Mr Faulding said if Nicola has drowned and her body was carried further down the river, his team can cover around 10 miles a day with the sonar.
SGI normally cover all diving operations for the police in the south-east of England, except for London.
