Survival rafts contain water sensors which trigger the compressed air cylinder to inflate the raft when dropped into the sea or a lake or a river. To prevent against accidental inflation, a reed switch is placed in the control circuit of the raft which is activated with a magnet on the outside of the case. Before the raft can be used, it needs to be taken out of the case which then takes the magnet away from the reed switch. This activates the water sensor and the homing beacon. Reed Switches are also used in emergency locator transmitters (ELT) to prevent the unit from transmitting when inside the cover. This is also achieved in a similar manner, by placing a magnet inside the pocket of the cover and mounting a reed switch inside the ELT. This keeps the ELT from transmitting as long as it is inside its cover. Such applications use normally open or normally closed type reed switches depending on the control circuit logic.