Tandem Skydiving Lessons. Tandem Freefall Jumps.
Audible altimeters are a backup to visual altimeters.
A commonly used device is the Cypress. The course includes 7 levels . In rare cases, when you exerience a malfunction , you use the reserve. The main parachute does not work properly. There are different degrees of malfunctions, some minor that can be easily corrected, some major which require you to use the reserve parachute.