The dice game of Yahtzee has nothing to do with yachts, but there are jokes.
       
“Yachtzee: What a child, or another person, may say when they see this type of boat” was posted on the newsgroup rec.games.computer.ultima.dragons on January 31, 2006. “yachtzee. I think I found my next boat” was posted on Twitter by Tommy Kasperski on September 16, 2009.
     
“What do you have when you get five yachts? Yachtzee!” was posted on Twitter by Steve Landey on April 13, 2010. “I saw 5 boats down at the marina that were exactly the same. Yachtzee!” was posted on Twitter by Whimsical Wordsmith on August 21, 2012. “I have 5 of the same boat ..... Yachtzee?” was posted on Twitter by Mr. Isno’t on January 17, 2013. “What do you say when you have five yachts? Yachtzee” was posted on Twitter by Danny Goforth on March 31, 2016. “@ExcuseThePun What do you call five of the same boats together? Yachtzee!” was posted on Twitter by Brian Mazzarella on August 1, 2017.
         
“When you play Yahtzee on a boat it’s called ‘Yachtzee’” was posted on Twitter by Alan F Giles on May 2, 2017. “If I played Yahtzee on a boat, would it called Yachtzee?” was posted on Twitter by Ben Phillips on October 8, 2018. “Late night thought: If you play Yahtzee on a boat, is it spelled Yachtzee?” was posted on Twitter by Bryan Kastelan Comedian on February 20, 2020. “If you were playing a Dice based board game on a large boat would it be called. Would it be called. Would it be called Yachtzee” was posted on Twitter by “benadryl spider nightmares online .com” on May 20, 2021.
 
“Have you heard about the game where you throw dice to win boats? Yachtzee!” was posted on Reddit—3amjokes on January 4, 2022.
 
“What is a Russian oligarch’s least favorite dice game?”/“Yacht seized” is a joke that was told following the 2022 Russian invasion of Ukraine.
       
         
Wikipedia: Yahtzee
Yahtzee is a dice game made by Milton Bradley (a company that has since been acquired and assimilated by Hasbro). It was first marketed under the name of Yahtzee by game entrepreneur Edwin S. Lowe in 1956. The game is a development of earlier dice games such as Poker Dice, Yacht and Generala. It is also similar to Yatzy, which is popular in Scandinavia.
 
The objective of the game is to score points by rolling five dice to make certain combinations. (...) A Yahtzee is five-of-a-kind and scores 50 points, the highest of any category. The winner is the player who scores the most points.
   
Google Groups: rec.games.computer.ultima.dragons
Puns and wordplay2
B2D
Jan 31, 2006, 8:14:53 AM
(...)
Yachtzee: What a child, or another person, may say when they see this type of boat.
   
Twitter
Tommy Kasperski
@Tommyskat
yachtzee. I think I found my next boat.
10:04 PM · Sep 16, 2009·Twitter Web Client
     
Twitter
Steve Landey
@irskep
What do you have when you get five yachts? Yachtzee!
2:55 PM · Apr 13, 2010·Silver Bird
 
Twitter
Chase Reynolds
@ChaseReynolds
I wish I had enough boats to play Yachtzee.
6:10 PM · Sep 22, 2011·Twitter Web Client
   
Twitter
Drew DiSabatino
@ddisabatino
If I ever owned a large boat I would name it “Yachtzee” which probably explains why I’ll never own a large boat.
8:22 AM · Mar 5, 2012·Twitter Web Client
   
Twitter
Whimsical Wordsmith
@Whimsical84
I saw 5 boats down at the marina that were exactly the same. Yachtzee!
6:48 AM · Aug 21, 2012·Twitter for iPhone
   
Twitter
Mr. Isno’t
@thorericpaul
Replying to @SteveMartinToGo
@SteveMartinToGo @billcollage_ I have 5 of the same boat ..... Yachtzee?
4:50 PM · Jan 17, 2013·Twitter for iPhone
   
Twitter
Zak Accuardi
@zaccuardi
A really rich friend just picked five huge boats at random and ended up with all the same kind. YACHTZEE
1:35 PM · Feb 28, 2013·Twitter for Android
   
Twitter
Reverbal
@ReverbalAbuse
Rollin’ with so many boats they call me Yachtzee.
11:22 PM · Oct 22, 2014·Twitter for Android
   
Twitter
Stephen Young
@amanaplanacanal
One day I’m gonna line up all five of my boats and finally win that freaking game of Yachtzee
instagram.com
Stephen Young (@dadxpunk) • Instagram photo
6:02 PM · Jun 6, 2015·Instagram
     
Twitter
Danny Goforth
@DannyGofo
What do you say when you have five yachts?
Yachtzee
11:58 AM · Mar 31, 2016·Twitter for iPhone
 
Twitter
Rob Judge
@thesportsjudge
What’s a fun game to play on a fancy boat ?
Yachtzee
7:45 PM · Jun 12, 2016·Twitter for iPhone
   
Twitter
Alan F Giles
@alanfgiles
When you play Yahtzee on a boat it’s called “Yachtzee.”
12:05 PM · May 2, 2017 from Chicago, IL·Twitter for iPhone
   
Twitter
Brian Mazzarella
@Mazzsays
@ExcuseThePun What do you call five of the same boats together?
Yachtzee!
12:08 AM · Aug 1, 2017·Twitter for Android
   
Twitter
Ben Phillips
@captainredface
If I played Yahtzee on a boat, would it called Yachtzee?
6:36 AM · Oct 8, 2018·Twitter for iPhone
   
Twitter
crosea
@CroseaNL
dice game on a boat
yachtzee
1:26 PM · May 30, 2019·TweetDeck
   
Twitter
Bryan Kastelan Comedian
@bkdoescomedy
Late night thought: If you play Yahtzee on a boat, is it spelled Yachtzee?
1:22 AM · Feb 20, 2020·Twitter for iPhone
   
Twitter
benadryl spider nightmares online .com
@Slashscreen
If you were playing a Dice based board game on a large boat would it be called. Would it be called. Would it be called Yachtzee
7:31 PM · May 20, 2021·Twitter for iPhone
 
Reddit—3amjokes
Posted by u/thomasbrakeline January 4, 2022
Have you heard about the game where you throw dice to win boats?
Yachtzee!