bit of a vague question.. But if it has set sail that means you obtained what you needed from the seasick captain being the HM cut,once it's gone its gone.
There is no hm called sail from Generation 1 all the way to the current Generation 4 or 5. However, it is a hm called Surf which can be obtained in Wally's house after beating your father in the gym.
Joseph Banks sailed on HMS Endeavour, a British Royal Navy research vessel.
The orbiter is named after HM Bark Endeavour, the ship commanded by 18th century explorer James Cook; the name also honored Endeavour, the Command Module of Apollo 15. This is why the name is spelled in the British English manner, rather than the American English spelling of "Endeavor." Reference: http://en.wikipedia.org/wiki/Space_shuttle_endeavour.
It wont leave until you've talked to the cut master and got the Cut HM. Afterwards it doesn't really matter.
James Cook, who was not yet a Captain but a Lieutenant, travelled to Australia in the HM Bark Endeavour.
use the HM cut
Cook's first boat was the HM Bark Endeavour, followed by The Resolution.
Surf on the river in New Bark Town. The road's pretty straightforward from there.
It's believed to be on the seabed of Narragansett Bay (Rhode Island). Attempts have been made to verify this, but too little evidence exists. In 2006, it was decided to not raise the wreck believed to be the Bark Endeavour.
The Endeavour
The only way to do this is have another game that has a Pokemon that knows Cut, and trade it over. Otherwise, you'll have to go on the ship to get the HM yourself, and it'll sail away.