At the time, Trump was almost bankrupt and looking to make some fast cash, reportedly selling the yacht to Prince Alwaleed bin-Talal for one third less than he paid for it.
In 1995, Trump also sold New York City's Plaza Hotel to Alwaleed and Singaporean investors for $325 million. In turn, they sold it nearly a decade later for $675 million. In July, Alwaleed's Kingdom Holding Company re-purchased the Plaza along with a New York-based firm.
In November 2017, Crown Prince Mohammed bin Salman, also known as MBS, launched a supposed anti-corruption purge largely seen as a consolidation of his power, arresting several Saudi princes and business leaders.
Alwaleed was one of those MBS had detained, forced to stay at Riyadh's Ritz-Carlton for 83 days. You can read more about that here.