Do I know him?
Maybe not, because he keeps a low profile, but Mr Dubens has been one of Britain's most successful entrepreneurs over the past two decades.
His latest deal, announced yesterday, saw Oakley, the AIM-listed private equity company he runs, spend just over £15m on a 66 per cent stake in Time Out New York. Oakley already has a 50 per cent stake in the UK business of the listings magazine.
What else has he done?
The list is endless. Remember those very Eighties T-shirts that used to change colour according to your body temperature? They were made by one of Mr Dubens' companies. He's best known as the man who bought internet service provider Pipex and then sold it on at a large profit to Tiscali. He also invested in 365 Media, the dot.com business that became a major entertainment and news service. He sold it to Sky for £100m a few years back.
Any other interesting ventures?
PJ Smoothies was fun – he was the Pete in "Pete & Johnny's", the duo on which the brand was based. That business got sold to Pepsi for £20m.
Who was Johnny?
Jonathan Sieff, one of the Sieff dynasty linked to Marks & Spencer. Mr Dubens met him through a school friend and they have often teamed up as business partners – the T-shirt business was a joint venture. Not that Mr Dubens lacks other connections: friends include Sir Philip Green, chef Tom Aikens and the Wolfson brothers – both Simon, the boss of Next, and Andrew, who is another colleague.
Not that we know of. He was linked with a bid for Friends Reunited a couple of years back, which might have been tough to make money from, but the deal didn't happen. He was too smart to overbid when someone else came in for the firm.
Watch this space. But, aged 42, Mr Dubens isn't planning to spend a great deal more time sailing, his big love, just yet. Once a driver for Joe Lewis, the billionaire businessman, he's still on the move.