“When is the best time to buy a boat?”/“When it’s on sail.”

A boat riddle is:
 
Q: When is the best time to buy a boat?
A: When it’s on sail (sale).
 
The “sail/sale” pun was posted on Twitter on March 25, 2010.
 
   
Twitter
Irv Segal‏
@IrvingSegal
Daily “Pun”-ishment…When is the best time to buy a boat? When it is on “sail”!
9:55 AM - 25 Mar 2010
 
Twitter
Vince Luciani‏
@vinnychenz13
Looking to buy a boat, I hear they’re rarely on ‘sail’ though…
5:15 PM - 2 Dec 2010
 
Twitter
kurree‏
@kurreesoup
When’s the best time to buy a new ship?
When its on sail
1:04 PM - 7 Apr 2013
   
Twitter 
HMM‏
@HoustonMaritime
Nautical Joke Wednesday!
When is the best time to buy a new ship?
When it’s on sail.
9:33 AM - 12 Mar 2014
 
Pirate’s Quest
Top Ten Pirate Jokes: Howell Davis’ Howlers!
Posted on 30th March 2017 at 10:50 am.
Written by nikki
(...)
Q5: When’s the best time to buy a pirate ship?
A: When it’s on sail
     
Reddit—Dad Jokes
When’s the best time to buy a boat? (self.dadjokes)
submitted April 30, 2017 by jcdcwassup
When they’re on sail.
 
Twitter
Dad Jokes‏
@GoodOldDadJokes
When’s the best time to buy a boat?
When they’re on sail.
#dadjokes
7:00 PM - 1 May 2017