The task is to identify the correctly spelled word from the given options. Let's analyze each option:
Demurrage: This is the correct spelling. "Demurrage" refers to the charges that the charterer pays to the shipowner for the delay in loading or unloading beyond the agreed-upon time.
Dimurrage: This is incorrect. The double 'm' and 'r' suggest a common error in spelling the word "Demurrage".
Demurage: This is incorrect because it omits the double 'r'.
Demerage: This is incorrect as it misses both the double 'r' and 'm'.
Therefore, the word that is correctly spelled is "Demurrage".