Originally Posted by Leapy
The blurb says you can initiate a self test function
To activate properly you have to pull (hard) to remove the cap, this lets the antenna unravel with a suitably impressive boing and reveals the on button.
The test button, unusually for a beacon, is also the cancel button.
Under the cap is an entire area which lights up when flashing the morse code for "help help, send helicopters and rum".
The floating pouch of delights is designed to hold the activated device with the antenna out and the GPS receiver face up, not that I think this would last in a F8 mind you.