What must be checked on the round regarding the IC Gyro?

Focusing on the correct answer: checking the transducer and through-hole fitting is vital for the functioning of the IC Gyro. The transducer converts various forms of input (like angular velocity) into electrical signals, which are then processed to ascertain the vessel's course. Ensuring that the through-hole fitting is secure is equally important, as it provides an effective seal for the gyro and prevents potential leaks or malfunctions. Any issues with these components can lead to inaccurate readings, thereby affecting navigation and safety on board.

While checking power supply and calibration is important, as well as monitoring heading accuracy, identifying issues with the transducer and through-hole fitting is fundamental to maintaining the integrity of the gyro's operation. Hence, the focus on these components plays a crucial role in ensuring reliable performance during navigation.