The boat isn’t listed in Putin’s official list of assets.
“Putin’s official financial disclosure, released annually by the Kremlin, lists his 2020 income at about $140,000. The only assets he claims: ownership of three cars, a trailer, an 800-square-foot apartment and a 200-square-foot garage, plus the use of a 1,600 square-foot apartment and two parking spaces.”
https://webcache.googleusercontent.com/search?q=cache:q4sYvsbVciYJ:https://www.forbes.com/sites/forbeswealthteam/2022/01/27/as-biden-mulls-sanctions-three-theories—on-how-putin-makes-his-millions/&cd=19&hl=en&ct=clnk&gl=us
Doesn’t sound much different than Biden to me.