My system (which is "official") has a lanyard that feeds down through the frame to a handle on the transom. Yank the handle, and about 4 seconds later, you have a sausage that's about 7' long and about 24" in diameter. I have been cautioned that in the event I actually need to use this thing, that you need to tether myself on a longish line to the boat. Otherwise, when the tube blows, the boat acts as a sail (assuming it was dang windy when you dumped!) and you loose your boat... totally! I suppose the only thing worse that an upside down RIB is an upside down RIB that is drifting away faster than you can swim.
I'm waiting for some smart-ass to tie a chord to the handle when I'm parked/docked someplace... Should cause an interesting show when I drive away!
Incidently, the re-boating plan isn't looking so hot all of a sudden... 30 cm last night... although most of it blew right past my place!