Combining the 'very, very largest yachts' comment in "Private Flying is Booming. But Parking Space for All Those Jets Is at Premium."
(European Commission exempts yachts up to 5000 gross tonnes from decarbonization regs)
With the Ukrainian diaspora comment in "Are Ukrainian Farmers an Endangered Species?".
(Ukraine has lost a lot of brainpower since 1991)
We get this:
That is the catamaran yacht-support-vessel Nebula (68 m/224 ft) crew: 10; guests: 8 via Superyacht|Fan.
The boat it supports doesn't make the list of the 25 longest yachts (cut-off: 124.4 m) but at 99.95 m (327 ft) Moonrise is not tiny:
Again, via Superyacht|Fan, crew: 32; guests: 16
Both are owned by Ukrainian-American Jan Koum.
He co-founded and sold WhatsApp to Mark Zuckerberg.
Now (2022) his boat has a boat.
And Moonrise, at
3,900 GT, won't be bothered by those pesky EU carbon rules.