Paquebot Post Office?

I saw this old Brunei stamp on ebay. Do you know what's unusual about it?What's unusual about it is the postmark. Postmarks are usually done at the post office where the letter is posted. If it is posted in Kuala Belait, it will be postmarked Kuala Belait. Tutong etc. Notice on this stamp, it says Paquebot. But we do not have a post office with the name of Paquebot. If you can find one, let me