I've had some time to read all the threads and come up with some opinions on what happened that night....see what you guys think (just my opinion!!)
SS is nervous about seeing step father and others in Castle Rock. Since her mother's death and other things (timeframe also seems to be around her DUI arrest IIRC) so this may have brought back many feelings and lots of anxiety.
RS senses she is feeling anxious, out of sorts, maybe drinking. They have words (disagreement, maybe) and she wants to be left alone (leaves cell phone) and just drive with Az.
I feel she might have taken anti-anxiety meds (often in addicts, if one is good, more is better) or maybe took another medication that we don't know about. Maybe a drink or two and headed out.
On the way, she feels increasingly anxious, maybe rethinking even coming. RS is on a motorcycle "catching up" to her. She makes some weird stops - I think she's disoriented. Buys wine which may add to the other thinks she took or drank before she left.
Decides to go some place to "sleep it off or mentally prepare". Needs to have a cover story so she makes a few calls. If Az is asked, he can say "mom stopped everywhere asking for directions, we were so lost!". Maybe talks about an accident or a fall as another cover - or tells him if anyone asks, that's what happened.
They make it to the beach, back in. Az watches a DVD in the back, mom is in the back sleeping. Az might fall asleep or maybe stays awake. Needs to leave the van for some reason (bathroom??). Mom wakes, realizes he isn't there; tries to find him. maybe realizes he's in the water....opens the door/hatch regardless of the water to use the light from inside to see. Goes in the water to look for him...drowns.
Maybe this is what happened....and maybe I'm crazy.
Regardless, I dont' think she planned it. I think it was a tragic accident by all accounts. I think if she ran off, someone else would be mysteriously missing....an ex, a new flame, whatever. I don't see that as being a valid option.
This is just my opinion...take it or leave it
