How many ELTs are required if you carry more than one life raft?

Carrying more than one life raft on an aircraft mandates a specific safety requirement for emergency location equipment. According to aviation regulations, when there are multiple life rafts on board, you typically need additional emergency locator transmitters (ELTs) to ensure that each life raft can independently signal for help in the event of an emergency.

Having two ELTs or one ELT along with one portable ELT provides a fail-safe mechanism because if one life raft becomes separated from the airplane post-ditching, the ELT attached to that raft can activate and transmit a distress signal to guide rescuers. This requirement enhances the safety measures for passengers and crew by increasing the likelihood that the aircraft's position will be known in the event of an incident over water.

Thus, option C correctly outlines that having two ELTs or a combination of an ELT and a portable ELT is necessary when multiple life rafts are in use, ensuring adequate safety measures are in place.