A pirate riddle (popular on International Talk Like a Pirate Day on September 19th) is:
   
Q: What’s a pirate’s favorite kind of socks?
A: Arrrrgyle.
 
The pirate joke was posted on the newsgroup alt.tv.xena on March 1, 1998.
   
         
Wikipedia: Argyle
An argyle (occasionally argyll) pattern is made of diamonds or lozenges. The word is sometimes used to refer to an individual diamond in the design, but more commonly refers to the overall pattern. Most argyle contains layers of overlapping motifs, adding a sense of three-dimensionality, movement, and texture. Typically, there is an overlay of intercrossing diagonal lines on solid diamonds.
 
The argyle pattern derives from the tartan of Clan Campbell, of Argyll in western Scotland, used for kilts and plaids, and from the patterned socks worn by Scottish Highlanders since at least the 17th century (see illustrations in History of the kilt). These were generally known as “tartan hose”.
           
Google Groups: alt.tv.xena
Lamia’s thought on “King Con”
julie e
3/1/98
(...)
I used to date a comic who was obsessed with pirates as comic material. Any thing said in a “pirate voice” was hilarious to him.  (What kind of socks do pirates wear? Arrrrrrgyles…yeah, real funny.

)
     
Google Groups: alt.callahans
For the Place’s Piratical Patrons, and Others
sylvia
12/11/99
(...)
What kind of socks do real pirates wear?
 
Argh-yle, of course!
 
The 914 Forums
Talk like a Pirate day!
GWN7
Sep 29 2004, 05:44 PM
(...)
4
what’s a pirate’s favorite kind of socks?
arrrrgyle
     
1 July 2005, Florida Times Union (Jacksonville, FL), “What is this?,” pg. SU-19:
By the way, do you know what kind of socks a pirate wears? Arrrrrgyle (an oldie but a goodie).
   
9 July 2006, The Desert Sun (Palm Springs, CA), “Pirate jokes,” pg. E2, col. 6:
Q: What kind of socks do pirates wear?
A: ARRRgyle.
 
tapatalk
really stoopid/lame jokes
nivek
03 Dec 2007, 13:34 #227
(...)
what’s a pirate’s favorite kind of socks?
arrrrgyle
 
Google Books
A Pirate’s Heart
By Catherine Friend
New York, NY: Bold Strokes Books, Inc.
2008
Pg. ?:
And Phyllis proved to be a great source for pirate jokes, such as: What kind of socks do pirates wear? Arrrghyl socks.
   
Google Books
Ultimate Book of Jokes:
The Essential Collection of More Than 1,500 Jokes
By Scott McNeely
San Francisco, CA: Chronicle Books
2011
Pg. 153:
Q: What’s a pirate’s favorite kind of socks?
A: Arrrrgyle.
 
Google Books
Sport Illustrated Kids Baseball Jokes!
By Blake Hoena
North Mankato, MN: Stone Arch Books
2018
Pg. 56:
What kind of socks do the Pirates’ players wear?
Arrrrrgyle!