I agree that a PLB would be a good idea, but that wouldn't be my sole choice. Remember things, especially electronics, have a habit of failing. A mistake in construction, a weak or dead battery, etc, when you need them most. I would definently take basic pocket gear and a small PSK and work my way up from there. You may lose your main pack so have a few items in your pockets.
I was being facetious and didn't have time to respond more fully. I do want to clarify that while a PLB would be awesome to have, even if it works you're not instantly out of the woods. There are many situations where you might have to hunker down and wait for rescue for hours or even days. Say you're lost in the Alaska wilderness and a storm is rolling in; help might not reach you for some time even if they know where you are.
I always have survival gear. I should think anyone that's a fixture of a sight like this would! My kit varies a lot depending on where I'm going, the season, how remote, etc. But I always have some kind of shelter (eg HeatSheets bivy, plastic tarp, sleeping bag, space blanket etc etc), a knife, a light and a heavy dose of fire gear.
On an island in the middle of the ocean I would want to have some kind of gear to distill water. A solar still might work and of course a regular still if there's a good wood source to make fire. A reverse osmosis desalination device like boats have would be awesome but over my $300 limit.