I think if you look at the extreme things that can happen they fall into categories; TSHTF ashore and the boat is fine; the boat has problems and you need to leave but nothing is happening ashore; and all you-know-what breaks loose and both boat and shore are in trouble.

So long as the boat has no problems, your stuff on board is of use if you need to make your way home without normal transportation and supplies. If you could scrounge some food and a tarp for such a trip, and I imagine these are likely to be available, then I think your are doing ok. A blanket might be nice to take too.

If the boat has a problem and nothing ashore is really amiss, you seem fine, espcially on the Rivers. grab the lifejacket and just get off, if that time ever comes. If you can get off, you should not be too far from land and hopefully civilization. I think that if I wanted to add anything to your gear, it would be to maybe attach a lighter to your lifejacket or put a match or two inside one of the lights attached to it. If you ever went swimming in a hurry and were not close to civilization, a fire might help you dry out and get warm.

The last, worse-case scenario I see happening only during a hurricane or tsunami. In the worse-case, keep you alive first, because otherwise you cannot do anyone else any good. it's good that this is not the time of year for hurricanes and that is not an area known for tsunamis. I've never known of many companies that did not try to get their boats away from hurricanes.

Also, how about something for water, in case you need to mkae the long walk home from the boat. Something that can hold it and make it drinkable it. Might not be able to add it to the stuff this week, but it is a thought.