Which of the following is not required on a personal flotation device (PFD)?

A personal flotation device (PFD) is designed to provide buoyancy and improve a person's chances of staying afloat in water. While certain features can enhance safety, not all are mandated by regulations.

The presence of a whistle as part of a PFD serves a crucial safety function. It acts as a signaling device to attract attention in case of an emergency. Reflective tape is also required on PFDs, as it increases visibility, especially in low-light conditions, thereby enhancing the chances of rescue.

A carabiner, while useful for securing items or individuals, is not a required component of a PFD. It may be included in specific applications or designs but does not hold a necessity under standard regulations.

The requirement for a rescue beacon varies and may depend on the type of vessel or specific regulations in place; however, it is not a standard requirement for all PFDs. This distinction makes it clear why a rescue beacon would not be found on all personal flotation devices.