Why is it important to check the compass before and after installing a magnetic contact on a boat?

Checking the compass before and after installing a magnetic contact on a boat is important primarily because magnets can affect compass readings. A magnetic contact, by its nature, can create a magnetic field that interferes with the operation of the compass. This interference can result in inaccurate heading information, which is crucial for navigation. Ensuring the compass is functioning correctly after installation helps verify that the magnetic contact does not disrupt navigational accuracy, allowing the boat operator to maintain safe and efficient course plotting.

The other options do not directly relate to the impact of installing a magnetic contact on navigational tools. While securing the contact and ensuring proper operation are essential, they do not pertain to the specific concern of compass accuracy. Similarly, issues related to radio signals or calculating speed are not relevant to the magnetic influence on compass readings, making the focus on magnet interference the key reason for checking the compass in this scenario.