Which two main types of compasses are used on ships?

The choice highlighting the Gyro Compass and Magnetic Compass is the most accurate because these two compass types are fundamental for navigation on ships. The Gyro Compass works using the Earth's rotation to find true north, making it invaluable in providing a stable reference even in rough seas where magnetic interference may affect readings. It does not rely on magnetic fields, which means it remains accurate regardless of the ship's location and orientation.

On the other hand, the Magnetic Compass provides a reading based on the Earth's magnetic field, allowing mariners to determine direction relative to magnetic north. It is a traditional tool that has been used for centuries and remains essential as a backup for modern navigational systems.

Both compass types serve critical roles in maritime navigation, with the Gyro Compass offering precision and stability, while the Magnetic Compass provides a reliable and straightforward method of navigation, making the combination of these two the cornerstone of maritime compass technology.