We find the Gambit sailing some choppy seas; inside one of the crew informs Robert that the storm is a category 2 and the captain is reccomending they head back.
Oliver enters the scene walking down the cabin hallway to get a status from his father on the storm. He's followed by Sara looking for a bottle opener. Robert takes Oliver aside and tells him that 'that is not going to end well for either you, or her'. Wise words Robert, cheating on your girlfriend with her sister is never the chivalrous or wise thing to do.
Unsurprisingly, Oliver doesn't listen and goes back to the cabin he is sharing with Sara and assures her that her sister is never going to find out(would this really have ever worked c'mon). They have a drink, a little banter which starts to lead to something else. When everything goes sideways, literally, and Sara is swept out to sea.
Oliver is swept out to sea right behind Sara but he drifts close to the lifeboat his father and a member of the crew have gotten to. He's pulled in and frantically calls out to Sara, whom he can't find.