The name of the ships involved are suppressed, as well as aspects of the ranks of those involved, details of Navy business and details about the witnesses.
The woman says Ward pinned her down, groped her breasts and digitally penetrated her against her will, only stopping when another person entered the cabin.
Judge Ryan said the onus was on the Crown to prove the charge beyond reasonable doubt and not for Ward and his legal team to prove his innocence.
She said the Crown also had to prove the act itself, that the woman didn't give consent and Ward didn't "honestly believe" she was consenting.
In her hour and a half of summing up the case, the judge told the jury it was for them to decide the woman's credibility and reliability - whether they accepted the Crown's view that her inaccuracies were honest mistakes, or the defence's submission that "she not only got things wrong but she's lying to you".
"It's going to be about how you deal with those sorts of things."
When the woman gave evidence, she accepted she was mistaken about whether Ward told her "shh, let it happen" or "shh, stop struggling, let it happen", which hand he used to grab which breast and which side of the country their ship travelled after the alleged incident.
But Judge Ryan said witnesses on both sides made mistakes because memory was never totally accurate - Ward himself remembered the act clearly and said at no point was the woman struggling, but he had no recollection of how he got into her cabin.
Ward is no longer in the Navy, but remains a member of its Volunteer Reserve unit.