I intend to swim long distances, over 5 km, in open waters. I won't do it in shark infested water or anything alike, but there are still a lot of dangers, like jellyfishes.
I also want to do it self sufficient.
I suspect that I would need at least an auto inflating vest. But what should I look for when choosing one? If I would need to carry food and water how can I do it? Is there something like a floating bag that I can easily attach to myself?
Related to safety again, is there something like a radio buoy to emit a signal in case of emergency?
Any other tips if someone already did this?