Well, if we are looking at the 19th c. in America, swearing was considered offensive- taking the Lord's name in vain was, after all, breaking one of the Ten Commandments. There was a law on the books in England, the Profane Oath Act of 1745, that listed a series of fines for public swearing, and it wasn't repealed until 1967. Though enforcement doubtless had mostly stopped before then, fines for public swearing in localities , like Myrtle Beach, still exist. Avoiding such fines have resulted in some imaginative substitutes: whole books could be compiled of substitute mild expletives ( tabernacle! in Quebec, tarnation! in West Virginia...)

The implication here is that everyone on the ship is driven to cursing and swearing about something: that it's not a happy ship, and good to avoid! But it's worth remembering that there was often an expectation of formality, of respect, between the crew and the officers. In Richard Henry Dana's classic Two Years Before the Mast, he recounts serving under a captain who was anything but respectful of his crew, insulting and humiliating them. The work of a sailor was expected to be hard ( though Dana would later be a noted advocate of better treatment for them) , and a captain was expected to be firmly in charge of discipline, but Dana's captain was anything but an impersonal authority. Along the same lines, Greg Denning's Mr Bligh's Bad Language proposed that Bligh humiliating and insulting his officers and crew was the main cause of the Bounty mutiny, not his high level of discipline. The British navy had, generally, a very high level of discipline and administered harsh punishments for infraction of it. But , Denning proposes, Bligh broke the boundaries of respect between captain, officers and crew, and that became unforgivable.