Pontoon bridge in 638. The army of the Umayyad Caliphate built a pontoon bridge over the Bosporus in 717 during the Siege of Constantinople (717–718). The Carolingian army of Charlemagne constructed a portable pontoon bridge of anchored boats bound together and used it to cross the Danube during campaigns against the Avar Khaganate in the 790s. Charlemagne's army built two fortified pontoon bridges across the Elbe in 789 during a campaign against the Slavic Veleti. The German army of Otto the Great employed three pontoon bridges, made from pre-fabricated materials, to rapidly cross the Recknitz river at the Battle on the Raxa
Trimaran feat, Francis Joyon held the world record for solo circumnavigation of the world, set on January 20, 2008. The 51-year-old Frenchman circled the planet alone in 57 days, 13 hours, 34 minutes, 6 seconds in a trimaran. He beat British sailor Ellen MacArthur's record set in February 2005 for which she spent just over 71 days at sea. Francis Joyon and crew of five sailors; Dec 2016–Jan 2017; the Maxi trimaran "IDEC SPORT"; current absolute (wind or mechanically powered) fastest maritime circumnavigation, in 40 days 23 hours 30 minutes 30 seconds of sailing. Average speed of 26.85 knots (30.71 MPH),