Most of the advice above is all good with regard to dunker, liferafts, lifejackets, floats, comms etc etc. However, unless you are really well prepared from an experience and equipment point of view then such a flight is quite a big thing. I fly over the water all day, every day and I do as much training as I can and carry ALL the above kit EVERY time. Now, I don't know you from a bar of soap mate, but if you are having to ask "what should I take on a fairly long overwater flight across the Irish Sea" then I submit that you and your aircraft are not ready for such a task.
If it all goes belly up
and you end up going for a swim then you are going to become a statisic. Do yourself a favour, catch a commercial flight and spend the money you saved on a nice meal and a couple of bottles of red!
