Doing Supercar things | Koshi 51 Sea Trial

The Koshi 51 GranTurismo sits in a very specific segment of the performance boating market, where lightweight construction and high-speed capability are prioritised over traditional cruising comfort or long-range liveaboard design. This is a 16.2-metre platform built entirely from a carbon fibre monocoque structure, with the focus clearly on reducing displacement and maximising performance efficiency. At approximately 2,100 kg excluding engines, the hull weight is significantly lower than most boats in this size category. Power comes from four Mercury 500R outboards, delivering a combined 2,000 horsepower. On paper, this places the boat in the high-performance offshore category rather than conventional day boating. The design brief is not centred around extended onboard living or heavy systems integration. Instead, it focuses on speed, responsiveness, and reduced resistance through the water. This boat is for someone who already lives in the top tier of yachting and speed culture and is looking for a high-speed extension of that lifestyle, not a traditional boat. Thanks, Dan, THANKS TO OUR SPONSORS Mention Code DBL for discounts on Marine Mold Construction https://ms-marine.eu/ BOAT BUILDERS https://dansboatlife.com/boat-builders BOAT BUYERS https://dansboatlife.com/boat-buyers BOAT OWNERS https://dansboatlife.com/courses PRICE: https://www.koshigroup.com/contact/ Watch Part 1: https://youtu.be/FaPFpmyQAw4 00:00 Start 01:21 Speed test at 35 mph: smooth acceleration with no bow rise and 115L fuel consumption 02:29 Cruising at 50 mph: hull self-trims without trim tabs at 3,500 RPM and 200L/hr 03:11 Into-the-wind test at 50 mph navigating white caps and wave chop 05:32 High-speed turning maneuver: entering at 45 mph and exiting at 65 mph 06:12 Top-speed run reaching 85 mph at 5,100 RPM with excellent directional stability 08:17 Transitioning from open-water performance to close quarters maneuvering test 09:11 Close quarters handling: transverse thrust, bow thruster use, and predictable tracking 11:05 Overall driving impressions: accessibility, fuel efficiency, and ideal owner profile 13:44 Experience level requirements, comparable boats, and community engagement wrap-up