PLB & V sheet you have right.
OMS Dye (scroll down 5 items) http://www.omsdive.com/misc.html
The OMS® Dye marker is packaged in a water proof container rated to 330’ FSW, provides a highly visible fluorescent, environmentally friendly “dye slick” that lasts for 30 minutes and enables aircraft to quickly locate the lost diver. This “slick” can be seen for a mile or more. Current, wind and wave action will affect the shape and duration of the pattern. Meets MILSPEC: MIL-S-17890D.
Mostly I was using my AI, in a large bay, but also sometimes off shore. It was not unusual to be 5+ km from shore, but honestly, you don't have to be far from shore to get into trouble. Only a few months ago someone questioned clothes that I mentioned and said it was over the top because they only fish in a river, with a bank 100 meters away at most. 1 week later there is a news report of a kayak fisherman, almost drowned and with hypothermia saved from the very same river. Fell from his kayak, while trying to pull his anchor, in current.
As far as I am concerned, it does not matter if I am 500 meters or 5 km from shore, I need to be able to look after myself, if part of that is taken away and I need assistance. Then I will make myself seen and heard and also make it as safe and easy for my rescuers as possible, I at least owe them that, for risking themselves for me and my pleasure's.
Mind you, I am glad I do not need to carry a sidearm as well.