Yachts docked at Safe Harbor marina in Newport, R.I., Aug. 9, 2026. The private equity firm Blackstone paid $5.6 billion in early 2025 for Safe Harbor. (David Degner/The New York Times) By MURRAY CARPENTER Tanned and tousled after a sailing regatta on Narragansett Bay, more than a thousand people gathered last month at a large marina in Newport, Rhode Island, for three days of competitive racing, dockside dinners and drinks aboard superyachts.Events like these bring together people who,…