The body of murdered Meg Walsh would have stayed within 1km from where it was dumped in the River Suir, a Naval Service officer told the Central Criminal Court yesterday.
The 35-year-old woman's body was recovered from the river on October 15, 2006 -- two weeks after she disappeared, having died from blunt force trauma to her head.
Lieutenant Commander Eddie Mulligan, of the Waterford Naval Reserve, said Ms Walsh's body would have been found not long after it came to the surface.
He said there had been intensive searches of the Suir and surrounding rivers since Ms Walsh's disappearance and a body would have been spotted quickly.
The Naval Service officer said Ms Walsh's body would have stayed within a radius of 1km from where it was dumped.
A dead body would have sunk quickly "like a sack of potatoes" and would have stayed there until it reached "positive buoyancy". It would then rise quickly and would be easily visible "bobbing" on the surface.
Lt Cmdr Mulligan said there were several locations within a 1km radius that would have deep enough water to deposit a body. There had been some of the highest tides in 18 years from October 6 to 12 -- but by the 15th, the water level and flow had lessened.
He said Four Quay, a possible location on the same side of the river as the body was recovered, was "at night, a very dark place". A second location, Grattan Quay, not far from Rice Bridge, would also have been a "very concealed place at night time."
Her husband, bus driver Mr John O'Brien (41), with an address in Ballinakill Downs, Co Waterford, denies murdering her on a date between October 1, 2006, and October 15, 2006.
Caroline O'Connor told the court she saw a silver car parked by the gate into the Water Works, at Bell Lake, on the Dunmore Road, between 8.30 and 9pm, on Sunday, October 1.
The jury have previously heard that Ms Walsh's car was a silver Mitsubishi Carisma.
Ms O'Connor said the light was on inside the car and the front passenger seat was open. She said she did not see anyone in or near the car. "I thought it was quite odd and I kept going."
Eddie Gleeson, an engineer with O2, told the court that the last activity from Meg's mobile phone was at 1.59pm on Sunday October 1, when a call was made to her message service.
A call from a friend at 7.12pm did not get through. Mr Gleeson said this was because the network could not contact the phone. This could be because the battery was run down or taken, or because the phone was rendered unusable by being smashed or dropped in water or otherwise incapacitated.
Her phone was pinging off the Blenheim Hill mast, closest to the couple's house in Ballinakill Downs, for all the activity on Sunday.
Ivan O'Flynn, also an O2 engineer, told the court that Mr O'Brien's phone was pinging off the Cove Centre mast near the Uluru car park, where Meg's car was abandoned on at 10.03pm on October 2. A call was put through to Meg's phone at 9pm and several calls were made to his message service between 9.30 and 9.50pm. All these calls were bouncing off the Cove Centre.
The trial continues today.