The Canadian F1 race in Montreal is held on a track in the middle of the St Lawrence River on the Circuit Gilles Villeneuve. I wonder if there are other car racing tracks on river islands

According to the CBC, the event's economic impact on the gross domestic product (GDP) is $63 million (CDN). 

Interest in the race exploded after the NetFlix documentary series "Drive To Survive" provided a behind-the-scenes insight into F1's personalities and rivalries -- with people locked down during the COVID-19 pandemic binge watching the episodes.

Tickets for Sunday's race on resale sites were not for the faint hearted, with general admission going for over $500 while VIP suites topped $10,000. 

Hotels were also cashing in with rooms averaging more than $500 a night while AirBnB were asking from $1,000 to $4,000 a day for a downtown condo.

https://www.facebook.com/photo/?fbid=10225077075966876&set=a.1339413198215

https://www.devdiscourse.com/article/sports-games/2079066-motor-racing-montreal-the-winner-as-formula-one-makes-return