On 20 April, Superyacht News provided a helpful summary of the situation, arrests and locations.
https://www.superyachtnews.com/business/sanctioned-superyachts-in-europe-so-far
Any modest contributions for my time and ongoing expenses are welcomed! I have a page where you can do so, and where one-off contributions start as low as $3, at https://www.buymea3coffee.com/KoIvM842y