Answer:
Whistling seen as a bad practice by sailors because it challenges the sea is an example of pseudoscience.
Step-by-step explanation:
Pseudoscience literally means false science. It claims to be science but it is not scientific at all. It completely fails in a scientific scrutiny and it is not open to evaluation by other experts.
They are just beliefs and practised claimed to be factual even without any proper method used in developing the hypotheses.
False pseudo scientific claims can be harmful at times. An example is the propaganda against vaccination.