Horatio Chapple was sleeping in his tent when the bear went on the rampage, inflicting fatal injuries to his head and body, in the Arctic Ocean's Svalbard islands.
Lauren Beech, who was also on the expedition, said she also found out after the incident that local authorities had issued a warning about increased polar bear activities in recent months before the attack.
She said Horatio noticed the prints of the polar bear on August 3. She added: "We were advised by the leader they were approximately two to four days old and they were facing in the direction of base camp.
"I remember there was more than one there, one was very distinct and I remember several of us taking photos with this print."
She added: "It may make me sound naive but I remember thinking 'Wow, it's a polar bear footprint' but I do not remember it making me any more worried."
She continued: "I had heard rumours another group had seen a polar bear ... apparently there had been a warning issued by the authorities in Svalbard that there was heightened activity of bears, but I wasn't aware of that."
Miss Beech said she had been concerned about the tripwire around the camp and that she did not consider it to be "very robust".
She also questioned the action of leaders who asked the group for their views on whether a bear watch should be held on the night before the attack.
She said: "The leaders laid out why they thought a bear watch wasn't required - they said it was a low-risk area.
"I couldn't understand at the time. As a 16-year-old and a young person I had no knowledge of the area and I put my complete trust in the leaders' knowledge."
Fellow team member Scott Bennell-Smith backed a bear watch, but the decision had rested with the leaders.
The inquest continues.