Final answer:
In case of an error in the ship's deck log, the watch stander should strike through the error and then write the correct information with an explanation for the correction.
Step-by-step explanation:
When an error is made in the ship's deck log, the watch stander must never erase or obliterate the original entry. Instead, the watch stander should strike through the error with a single line, ensuring that the mistaken text is still legible. Then, the correct information should be entered nearby with an explanation for the correction. This action is necessary to maintain the integrity of the log as a legal document.