Thank you for your reply. I did think that, but needed to ask

Strictly from a loop structure standpoint, or within the framework of an at least partially physical/Bermuda Triangle interpretation, that'd be it, yes (if an afterlife interpretation she may not have that much control, meaning there may never be a circumstance where she'd die other than when she's "suppose" to). But if what you describe were to happen then Jess Prime/Jess 0, i.e. the Jess at the house in the morning, wouldn't be bashed in the head and therefore would be free to drive to the harbor, starting the cycle all over, at which time she'd interface with the last two Jess versions that are still finishing their loop (since there's a 3-loop overlap due to the asynchronous nature of her loop). In that way the cycle itself is perpetual and will never end. However, Jess' membership of that cycle is finite. She drove to the harbor and entered it, therefore one way or another (e.g. she chooses to not go home and kill herself, or not go on the yacht to try to save Tommy, or she dies prior to those points) she must also leave it (if not she could never enter it since the only way she can drive to the harbor and loop is if another version doesn't kill her at her house, or if at some point she chooses not to board the yacht after killing herself at the house, which I suggest would collapse the accumulations and start over).
For something more in-depth (plus a whole lot of extras) check the following out:
http://www.imdb.com/board/11187064/board/thread/223982092
http://sdrv.ms/MoXetr

I'm something new entirely. With my own set of rules. I'm Dexter. Boo.