Which is correct: “offshore” or “offshore”?

Offshore or offshore? How to write?

“Offshore” comes from the English Offshore (off + shore). Now this word can be called borrowed with confidence. However, in Russian it began to be mentioned with one letter “F”. We turn to the dictionary from 1999 (Russian Spelling Dictionary, edited by V.V. Lopatin). Offshore is spelled with one letter “F”. They even began to register sites with transliteration into Latin from Russian - "offshore" - to "ofshor". For example, ofshor dot ru.

However, businessmen and bankers, financiers and auditors, accountants and secretaries, IT specialists still speak and use "offshore".
The business turnover takes over and the word is more often plowed with two “ff”. Search engines Google and Yandex clearly say this.

Interestingly, the word "offshore" is often used incorrectly, not only in Russian. In Google queries, there are options for both Offshore banking and Offshore company.

Also interesting is the fact that the word “Onshore” appeared against the background of the use of “Offshore”.